Condensed Matter

Simultaneous measurement of electronic and vibrational dynamics to clarify a geometrical relaxation process in a conjugated polymer

Juan Du, Zhuan Wang, Wei Feng, Katsumi Yoshino, and Takayoshi Kobayashi
The real-time vibrational spectroscopy was utilized to obtain both electronic and vibrational dynamics in a conjugated polymer under the same excitation and probing condition by using the same sample and observing at the same time. Most of the conjugated polymers are in an amorphous phase, in which ... [Phys. Rev. B 77, 195205 (2008)] published Thu May 15, 2008.

Publisher's Note: Monte Carlo simulations of charge carrier mobility in semiconducting polymer field-effect transistors [Phys. Rev. B [bold 76], 155202 (2007)]

Lemi Demeyu, Sven Stafstrom, and Mulugeta Bekele
... [Phys. Rev. B 77, 199903 (2008)] published Thu May 15, 2008.

Impurity segregation and ordering in Si/SiO[sub 2]/HfO[sub 2] structures

A. G. Marinopoulos, K. van Benthem, S. N. Rashkeev, S. J. Pennycook, and S. T. Pantelides
We use first-principles calculations and experimental data to demonstrate that impurity segregation at heterointerfaces is governed by several factors. In particular, Hf impurities avoid the Si-SiO interface when present in the SiO side, might segregate if present in the Si side, but do not cross in ... [Phys. Rev. B 77, 195317 (2008)] published Thu May 15, 2008.

Solid-state dewetting-mediated aggregation of nanoparticles

J. S. Palmer, P. Swaminathan, S. Babar, and J. H. Weaver
The deposition of Au onto thin Xe films at a low temperature leads to cluster formation. The subsequent Xe sublimation results in cluster aggregation and delivery to the substrate in a process known as buffer-layer-assisted growth. Previously, this process was described in terms of a diffusion-limit ... [Phys. Rev. B 77, 195422 (2008)] published Thu May 15, 2008.

Zone-center instability of C(5,0) carbon nanotubes inside AlPO[sub 4]-5 channels

M. V. Fernandez-Serra and X. Blase
The electronic structure of C(5,0) carbon nanotubes inside zeolite channels is analyzed. We confirm the occurrence of the metal-semiconductor transition which has been previously predicted in the case of isolated tubes. The interaction with the zeolite matrix does not prevent the spontaneous metal-s ... [Phys. Rev. B 77, 195115 (2008)] published Thu May 15, 2008.

Iterative real-time path integral approach to nonequilibrium quantum transport

S. Weiss, J. Eckel, M. Thorwart, and R. Egger
We have developed a numerical approach to compute real-time path integral expressions for quantum transport problems out of equilibrium. The scheme is based on a deterministic iterative summation of the path integral for the generating function of the nonequilibrium current. Self-energies due to the ... [Phys. Rev. B 77, 195316 (2008)] published Thu May 15, 2008.

Electromagnetic response and pseudo-zero-mode Landau levels of bilayer graphene in a magnetic field

T. Misumi and K. Shizuya
The electromagnetic response of bilayer graphene in a magnetic field is studied in comparison to that of monolayer graphene. Both types of graphene turn out to be qualitatively quite similar in dielectric and screening characteristics, especially those deriving from vacuum fluctuations, but the effe ... [Phys. Rev. B 77, 195423 (2008)] published Thu May 15, 2008.

Refraction of surface plasmon-polaritons at Au-Al boundaries observed by scanning near-field optical microscopy

Tazuko Kitazawa, Shintaro Miyanishi, Yoshiteru Murakami, Kunio Kojima, and Akira Takahashi
Surface plasmon-polariton (SPP) propagation was investigated experimentally on a heterostructured metal sample consisting of in-plane Al and Au films. A scattered-type scanning near-field optical microscope (SNOM) was used to observe the wave vector and intensity of the SPPs. Interference fringes ap ... [Phys. Rev. B 77, 193404 (2008)] published Thu May 15, 2008.

Short-range and long-range contributions to the size effect in metal-ferroelectric-metal heterostructures

A. K. Tagantsev, G. Gerra, and N. Setter
The size-effect problem in metal-ferroelectric-metal heterostructures is analyzed in terms of the multiscale schemewhich combines phenomenology and first-principles calculationsrecently developed by the authors. We demonstrate how this effect can be separated into two distinct contributions: a long- ... [Phys. Rev. B 77, 174111 (2008)] published Thu May 15, 2008.

Temperature-dependent electronic structure of the colossal magnetoresistive manganite La[sub 0.7]Sr[sub 0.3]MnO[sub 3] from hard x-ray photoemission

Francesco Offi, Norman Mannella, Tommaso Pardini, Giancarlo Panaccione, Andrea Fondacaro et al.
We have studied in situ fractured surfaces of single-crystal LaSrMnO with hard x-ray photoemission (HXPS) at an excitation energy of 7.7 keV. These more bulk-sensitive measurements reveal low-binding-energy satellites in the Mn 2p, 3s, and 3p core spectra that are in agreement with previously observ ... [Phys. Rev. B 77, 174422 (2008)] published Thu May 15, 2008.

Finite element analysis of a crack tip in silicate glass: No evidence for a plastic zone

T. Fett, G. Rizzi, D. Creek, S. Wagner, J. P. Guin et al.
Recently, the claim was made that cracks in silicate glasses propagate by the nucleation, growth, and coalescence of cavities at crack tips, which is the same way as in metals but at a much smaller scale. This hypothesis for crack growth is based in part on the measurement of surface displacements n ... [Phys. Rev. B 77, 174110 (2008)] published Thu May 15, 2008.

Magnetic properties of Fe-Pd magnetic shape memory alloys: Density functional calculations and epitaxial films

J. Buschbeck, I. Opahle, S. Fahler, L. Schultz, and M. Richter
The magnetic properties of Fe-Pd magnetic shape memory alloys with different Pd contents are investigated in epitaxial films and by means of density functional calculations. The magnetocrystalline anisotropy energy (MAE) of ordered and disordered Fe-Pd alloys is calculated as a function of c/a ratio ... [Phys. Rev. B 77, 174421 (2008)] published Thu May 15, 2008.

Interface magnetism in Fe[sub 2]O[sub 3]/FeTiO[sub 3] heterostructures

Rossitza Pentcheva and Hasan Sadat Nabi
To resolve the microscopic origin of magnetism in the FeO/FeTiO system, we have performed density functional theory calculations that take into account on-site Coulomb repulsion. By systematically varying the concentration, distribution, and charge state of Ti in a hematite host, we compile a phase ... [Phys. Rev. B 77, 172405 (2008)] published Thu May 15, 2008.

Chromium at high pressures: Weak coupling and strong fluctuations in an itinerant antiferromagnet

R. Jaramillo, Yejun Feng, J. C. Lang, Z. Islam, G. Srajer et al.
The spin- and charge-density-wave order parameters of the itinerant antiferromagnet chromium are directly measured with nonresonant x-ray diffraction as the system is driven toward its quantum critical point with high pressure using a diamond anvil cell. The exponential decrease of the spin and char ... [Phys. Rev. B 77, 184418 (2008)] published Thu May 15, 2008.

Magnetic polarization of noble metals by Co nanoparticles in M-capped granular multilayers (M = Cu, Ag, and Au): An x-ray magnetic circular dichroism study

J. Bartolome, L. M. Garcia, F. Bartolome, F. Luis, R. Lopez-Ruiz et al.
X-ray magnetic circular dichroism spectra have been recorded at the L edges of Co, Cu, Ag, and Au, and at the K edges of Co and Cu for a series of multilayer systems of partially self-assembled Co nanoparticles, both capped with alumina and with different metals (Cu, Ag, and Au). The orbital and spi ... [Phys. Rev. B 77, 184420 (2008)] published Thu May 15, 2008.

Surface deformation caused by the Abrikosov vortex lattice

Pavel Lipavsky, Klaus Morawetz, Jan KolaCek, and Ernst Helmut Brandt
In superconductors penetrated by Abrikosov vortices, the magnetic pressure and the inhomogeneous condensate density induce a deformation of the ionic lattice. We calculate how this deformation corrugates the surface of a semi-infinite sample. The effect of the surface dipole is included. ... [Phys. Rev. B 77, 184509 (2008)] published Thu May 15, 2008.

Low-temperature dynamics of magnetic colloids studied by time-resolved small-angle neutron scattering

A. Wiedenmann, U. Keiderling, M. Meissner, D. Wallacher, R. Gahler et al.
The dynamics of ordering and relaxation processes in magnetic colloids has been studied by means of stroboscopic small angle neutron scattering techniques in an oscillating magnetic field. Surfactant stabilized ferrofluids (FFs) of FeO and Co nanoparticles have been investigated as a function of tem ... [Phys. Rev. B 77, 184417 (2008)] published Thu May 15, 2008.

Spin solitons and spin waves in chiral and racemic molecular based ferrimagnets

R. Morgunov, M. V. Kirman, K. Inoue, Y. Tanimoto, J. Kishine et al.
Resonant modes corresponding to a spin-soliton resonance (SSR) and a spin-wave resonance (SWR) have been detected and distinguished in the spectra of the electron spin resonance (ESR) of two-dimensional [Cr(CN)][Mn(S)-pnH-(HO)]HO [green needle (GN)] chiral single crystals and three-dimensional [Mn{( ... [Phys. Rev. B 77, 184419 (2008)] published Thu May 15, 2008.

Stress orientation and relativistic effects on the separation of moving screw dislocations

Z. Q. Wang and I. J. Beyerlein
The subsonic motion of a fast-moving, extended screw dislocation in an fcc metal under constant stress is studied using continuum linear elastic dislocation theory and molecular dynamics (MD) simulation. In this regime, many phenomena predicted by the theory are shown to prevail in simulation, in pa ... [Phys. Rev. B 77, 184112 (2008)] published Thu May 15, 2008.

Transmittance and transparency of subwavelength-perforated conducting films in the presence of a magnetic field

Yakov M. Strelniker and David J. Bergman
We theoretically and numerically studied the transmission of light through a subwavelength-perforated metal film, as well as through a homogeneous metal film with a Drude ac conductivity tensor, in the presence of a static magnetic field. Both the perforated and the homogeneous metal films are found ... [Phys. Rev. B 77, 205113 (2008)] published Thu May 15, 2008.

Analytical study of the plasmonic modes of a metal nanoparticle circular array

Kin Hung Fung and C. T. Chan
We analyze the plasmonic modes of a metal nanoparticle circular array. Closed-form solutions to the eigenmode problem are presented. For each polarization, the plasmonic mode with the highest quality is found to be in antiphase. The significant suppression of radiative loss can be understood as the ... [Phys. Rev. B 77, 205423 (2008)] published Thu May 15, 2008.

Subnanosecond switching of local spin-exchange coupled to ferromagnets

Jonas Fransson
The dynamics of a single spin that is embedded in a tunnel junction between ferromagnetic contacts is strongly affected by the exchange coupling to the tunneling electrons. By using time-dependent equations of motion for the spin, which is under the influence of a spin-polarized tunneling current, i ... [Phys. Rev. B 77, 205316 (2008)] published Thu May 15, 2008.

Gauge field induced by ripples in graphene

F. Guinea, Baruch Horovitz, and P. Le Doussal
We study the effects of quenched height fluctuations (ripples) in graphene on the density of states (DOS). We show that at strong ripple disorder, a divergence in the DOS can lead to an ordered ground state. We also discuss the formation of dislocations in corrugated systems, buckling effects in sus ... [Phys. Rev. B 77, 205421 (2008)] published Thu May 15, 2008.

Plane-wave based electronic structure calculations for correlated materials using dynamical mean-field theory and projected local orbitals

B. Amadon, F. Lechermann, A. Georges, F. Jollet, T. O. Wehling et al.
The description of realistic strongly correlated systems has recently advanced through the combination of density functional theory in the local density approximation (LDA) and dynamical mean field theory (DMFT). This LDA+DMFT method is able to treat both strongly correlated insulators and metals. S ... [Phys. Rev. B 77, 205112 (2008)] published Thu May 15, 2008.

Theory of a Josephson junction detector of non-Gaussian noise

Hermann Grabert
The measurement of higher order cumulants of the current noise generated by a nonlinear mesoscopic conductor using a Josephson junction as on-chip detector is theoretically investigated. The paper addresses the regime where the noise of the mesoscopic conductor initiates activated escape of the Jose ... [Phys. Rev. B 77, 205315 (2008)] published Thu May 15, 2008.

Nature and strength of bonding in a crystal of semiconducting nanotubes: van der Waals density functional calculations and analytical results

Jesper Kleis, Elsebeth Schroder, and Per Hyldgaard
The dispersive interaction between nanotubes is investigated through ab initio theory calculations and in an analytical approximation. A van der Waals density functional (vdW-DF) [M. Dion et al., Phys. Rev. Lett. 92, 246401 (2004)] is used to determine and compare the binding of a pair of nanotubes ... [Phys. Rev. B 77, 205422 (2008)] published Thu May 15, 2008.

Nonlinear magnetotransport in microwave-illuminated two-dimensional electron systems

A. T. Hatke, H.-S. Chiang, M. A. Zudov, L. N. Pfeiffer, and K. W. West
We study magnetoresistivity oscillations in a high-mobility two-dimensional electron system subject to both microwave and dc electric fields. First, we observe that the oscillation amplitude is a periodic function of the inverse magnetic field and is strongly suppressed at microwave frequencies near ... [Phys. Rev. B 77, 201304 (2008)] published Thu May 15, 2008.

Bent graphite surfaces as guides for cluster diffusion and anisotropic growth

M. Schmidt, N. Kebaili, A. Lando, S. Benrezzak, L. Baraton et al.
The interaction between neutral silver clusters and graphite surfaces is studied by cluster deposition and aggregation experiments. It is shown that the cluster diffusion is strongly influenced by the surface curvature. Convexly bent areas act as repulsive barriers for the cluster diffusion. Bent ar ... [Phys. Rev. B 77, 205420 (2008)] published Wed May 14, 2008.

Periodic arrangements of chiral scatterers providing negative refractive index bi-isotropic media

L. Jelinek, R. Marques, F. Mesa, and J. D. Baena
The main goal of this contribution is to show that periodic arrangements of chiral scatterers can be the basis for the development of three dimensional and isotropic negative refractive index artificial media. Three dimensionality and isotropy are key issues in this context since only three dimensio ... [Phys. Rev. B 77, 205110 (2008)] published Wed May 14, 2008.

Quantum dot properties in the multiband envelope-function approximation using boundary conditions based upon first-principles quantum calculations

Curt A. Flory, Charles B. Musgrave, and Zhiyong Zhang
A number of physical processes involving quantum dots depend critically upon the evanescent electron eigenstate wave function that extends outside of the material surface into the surrounding region. These processes include electron tunneling through quantum dots, as well as interactions between mul ... [Phys. Rev. B 77, 205312 (2008)] published Wed May 14, 2008.

Charged coplanar semiconductor quantum rings: Magnetization and inter-ring electron-electron correlation

Bartlomiej Szafran
We study a coplanar system of electrostatically coupled semiconductor quantum rings each charged by a single electron using a configuration-interaction approach. We find that the electron densities confined in separate rings are significantly deformed by the inter-ring coupling which results in redu ... [Phys. Rev. B 77, 205313 (2008)] published Wed May 14, 2008.

Critical dopant concentration in polyacetylene and phase diagram from a continuous four-Fermi model

Heron Caldas, Jean-Loic Kneur, Marcus Benghi Pinto, and Rudnei O. Ramos
The optimized perturbation theory (OPT) method, at finite temperature and finite chemical potential, is applied to the field theory model for polyacetylene. The critical dopant concentration in trans-polyacetylene is evaluated and compared to available experimental data and to previous calculations. ... [Phys. Rev. B 77, 205109 (2008)] published Wed May 14, 2008.

X-ray absorption and x-ray magnetic dichroism study on Ca[sub 3]CoRhO[sub 6] and Ca[sub 3]FeRhO[sub 6]

T. Burnus, Z. Hu, Hua Wu, J. C. Cezar, S. Niitaka et al.
By using x-ray absorption spectroscopy at the Rh L, Co L, and Fe L edges, we find a valence state of Co/Rh in CaCoRhO and of Fe/Rh in CaFeRhO. X-ray magnetic circular dichroism spectroscopy at the Co L edge of CaCoRhO reveals a giant orbital moment of about 1.7[mu], which can be attributed to the oc ... [Phys. Rev. B 77, 205111 (2008)] published Wed May 14, 2008.

Publisher's Note: Thermodynamic states and phase diagrams for bulk-incoherent, bulk-coherent, and epitaxially-coherent semiconductor alloys: Application to cubic (Ga,In)N [Phys. Rev. B [bold 77], 205201 (2008)]

Jefferson Z. Liu and Alex Zunger
... [Phys. Rev. B 77, 209902 (2008)] published Wed May 14, 2008.

Multimode vibrational effects in single-molecule conductance: A nonequilibrium Green's function approach

R. Hartle, C. Benesch, and M. Thoss
The role of multimode vibrational dynamics in electron transport through single-molecule junctions is investigated. The study is based on a generic model, which describes charge transport through a single molecule that is attached to metal leads. To address vibrationally coupled electron transport, ... [Phys. Rev. B 77, 205314 (2008)] published Wed May 14, 2008.

Anisotropic magnetization and dynamic susceptibility sign change in single-crystal Na[sub 0.85]CoO[sub 2]

Jong-Soo Rhyee, J. B. Peng, C. T. Lin, and S. M. Lee
The dc and ac magnetic susceptibilities of NaCoO single crystals were measured for the different crystal orientations of H||(ab) and H||(c) axis. The dc-magnetic susceptibility for H||(c) direction exhibited the antiferromagnetic transition at T=22 K. The thermal hysteresis between the zero-field-c ... [Phys. Rev. B 77, 205108 (2008)] published Wed May 14, 2008.

Bosonization approach to the mixed-valence two-channel Kondo problem

A. Iucci and C. J. Bolech
We present in detail the bosonization-refermionization solution of the anisotropic version of the two-channel Anderson model at a particular manifold in the space of parameters of the theory, where we establish an equivalence with a Fermi-Majorana biresonant-level model. The correspondence is rigoro ... [Phys. Rev. B 77, 195113 (2008)] published Wed May 14, 2008.

Anderson impurity model in a semiconductor

Martin R. Galpin and David E. Logan
We consider an Anderson impurity model in which the locally correlated orbital is coupled to a host with a gapped density of states. Single-particle dynamics are studied within a perturbative framework that includes both explicit second-order perturbation theory and self-consistent perturbation theo ... [Phys. Rev. B 77, 195108 (2008)] published Wed May 14, 2008.

Optical excitation of nuclear spin coherence in a Tm[sup 3+]:YAG crystal

A. Louchet, Y. Le Du, F. Bretenaker, T. Chaneliere, F. Goldfarb et al.
A thulium-doped crystal is experimentally shown to be an excellent candidate for broadband quantum storage in a solid-state medium. The nuclear spin coherence is optically excited, detected, and characterized in such a crystal. The lifetime of the spin coherencethe potential storage entityis measure ... [Phys. Rev. B 77, 195110 (2008)] published Wed May 14, 2008.

Interference effects in the counting statistics of electron transfers through a double quantum dot

Sven Welack, Massimiliano Esposito, Upendra Harbola, and Shaul Mukamel
We investigate effects of quantum interferences and Coulomb interaction on the counting statistics of electrons crossing a double quantum dot in a parallel geometry by using a generating function technique based on a quantum master equation approach. The skewness and the average residence time of el ... [Phys. Rev. B 77, 195315 (2008)] published Wed May 14, 2008.

Effect of non-Fermi liquid behavior on the temperature dependence of the amplitude of de Haas-van Alphen oscillations

P. Schlottmann
We calculate the amplitudes of de Haas-van Alphen oscillations for a system of heavy fermions close to a quantum critical point (QCP). A nested Fermi surface, which consists of an electron and a hole pocket, together with the remaining interaction between the carriers after the heavy particles are f ... [Phys. Rev. B 77, 195111 (2008)] published Wed May 14, 2008.

Quantum kinetic equation and universal conductance fluctuations in graphene

K. Kechedzhi, O. Kashuba, and Vladimir I. Fal'ko
We analyze universal conductance fluctuations (UCFs) in graphene in the framework of diagrammatic perturbation theory in the metallic regime. It is shown that strong intervalley scattering lifts the valley degeneracy of electronic states, whereas at weak intervalley scattering two valleys independen ... [Phys. Rev. B 77, 193403 (2008)] published Wed May 14, 2008.

Erratum: Kinetic energy functional for a two-dimensional electron system [Phys. Rev. B [bold 76], 195103 (2007)]

M. Koivisto and M. J. Stott
... [Phys. Rev. B 77, 199902 (2008)] published Wed May 14, 2008.

Density-functional investigation of metal-silicon cage clusters MSi[sub n] (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn; n = 8--16)

Ling-ju Guo, Gao-feng Zhao, Yu-zong Gu, Xia Liu, and Zhi Zeng
The geometries, stabilities, electronic, and magnetic properties of the transition metal encapsulated MSi (M=Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn; n=816) clusters have been systematically investigated by using density functional theory with generalized gradient approximation. It is shown that every ... [Phys. Rev. B 77, 195417 (2008)] published Wed May 14, 2008.

Comparison between experimental surface data and bulk structure models for quasicrystalline AlPdMn: Average atomic densities and chemical compositions

Baris Unal, C. J. Jenks, and P. A. Thiel
We have examined bulk structure models for icosahedral AlPdMn in terms of the densities, compositions, and interplanar spacings for the fivefold planes that might represent physical surface terminations. We focus on four models that contain no partial or mixed occupancies, but some comparison is mad ... [Phys. Rev. B 77, 195419 (2008)] published Wed May 14, 2008.

Electronic structure and Fermi surface of Sn/Cu(100)-(3sqrt(2) x sqrt(2))R45[degree]

J. Martinez-Blanco, V. Joco, J. Fujii, P. Segovia, and E. G. Michel
The surface phase Sn/Cu(100)-(3sqrt(2) x sqrt(2))R45 degrees exhibits a temperature induced phase transition to a (sqrt(2) x sqrt(2))R45 degrees phase above 360 K. We report an angle-resolved photoemission study of the two-dimensional Fermi surface of the low-temperature phase. The Fermi surface ... [Phys. Rev. B 77, 195418 (2008)] published Wed May 14, 2008.

Highly efficient spatiotemporal coherent control in nanoplasmonics on a nanometer-femtosecond scale by time reversal

Xiangting Li and Mark I. Stockman
One of the main problems in nanoplasmonics is the active dynamic control of optical local fields. We propose an efficient method to solve this problem. It allows one to impose coherent control of the spatiotemporal localization of the optical excitation energy in nanoplasmonic systems on the nanomet ... [Phys. Rev. B 77, 195109 (2008)] published Wed May 14, 2008.

Unipolar transport and interface charge transfer in nanostructured CdTe/polymer hybrid films

Robert Meier, Robert C. Word, Athavan Nadarajah, and R. Konenkamp
We report detailed photoconductance measurements on hybrid semiconductor films consisting of CdTe nanoparticles in a poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene (MEH-PPV) matrix. Our results show that a staggered band alignment between organic and inorganic semiconductors produces an ... [Phys. Rev. B 77, 195314 (2008)] published Wed May 14, 2008.

Disorder-induced transverse delocalization in ropes of carbon nanotubes

M. Ferrier, A. Chepelianskii, S. Gueron, and H. Bouchiat
A rope of carbon nanotubes consists in an array of parallel single wall nanotubes with nearly identical diameters. In most cases, the individual nanotubes within a rope have different helicities and 1/3 of them are metallic. In the absence of disorder within the tubes, the intertube electronic trans ... [Phys. Rev. B 77, 195420 (2008)] published Wed May 14, 2008.

Low-energy collective dynamics of charge stripes in the doped nickelate La[sub 2 - x]Sr[sub x]NiO[sub 4 + delta] observed with optical conductivity measurements

J. Lloyd-Hughes, D. Prabhakaran, A. T. Boothroyd, and M. B. Johnston
We have investigated charge dynamics in the static stripe ordered phase of LaSrNiO at lattice temperatures below the charge ordering transition, via optical conductivity measurements at low energies (110 meV). The thermally activated dynamic response of the charge stripes is found to be characteris ... [Phys. Rev. B 77, 195114 (2008)] published Wed May 14, 2008.

Calculations of strain-modified anatase TiO[sub 2] band structures

Lukas Thulin and John Guerra
In order to theoretically quantify a strain-inducing method that we use to engineer the material properties of anatase titania, we studied its electronic band structure over a range of biaxial strain by utilizing both the density functional theory within the generalized gradient approximation (GGA) ... [Phys. Rev. B 77, 195112 (2008)] published Wed May 14, 2008.

Quantum transport of Dirac electrons in graphene in the presence of a spatially modulated magnetic field

M. Tahir and K. Sabeeh
We have investigated the electrical transport properties of Dirac electrons in a monolayer graphene sheet in the presence of a perpendicular magnetic field that is weakly and periodically modulated along one direction. We find that the Landau levels broaden into bands and their width oscillates as a ... [Phys. Rev. B 77, 195421 (2008)] published Wed May 14, 2008.

Nonradiative exciton energy transfer in hybrid organic-inorganic heterostructures

S. Chanyawadee, P. G. Lagoudakis, R. T. Harley, D. G. Lidzey, and M. Henini
Nonradiative energy transfer from a GaAs quantum well to a thin overlayer of an infrared organic semiconductor dye is unambiguously demonstrated. The dynamics of exciton transfer are studied in the time domain by using pump-probe spectroscopy at the donor site and fluorescence spectroscopy at the ac ... [Phys. Rev. B 77, 193402 (2008)] published Wed May 14, 2008.

Study of Ba and Zr stability in UO[sub 2 [plus-minus] x] by density functional calculations

G. Brillant and A. Pasturel
Barium and zirconium behavior in nuclear fuels is investigated using density functional theory (DFT). More particularly, incorporation and solution energies of Ba and Zr in preexisting trap sites of UO (vacancies, interstitials, U-O divacancy, and Schottky trio defects) are calculated using the proj ... [Phys. Rev. B 77, 184110 (2008)] published Wed May 14, 2008.

Effects of double-Gaussian disorder on the dynamics of the quantum XY chain

Zhen-Bo Xu, Xiang-Mu Kong, and Zhong-Qiang Liu
We investigate the dynamics of the random one-dimensional spin-1/2 quantum isotropic XY model in high-temperature limit by the recurrence relations method. Both the time-dependent transverse autocorrelation function and the corresponding spectral density are calculated for the cases that the exchang ... [Phys. Rev. B 77, 184414 (2008)] published Wed May 14, 2008.

Magnetic behavior of melt-spun gadolinium

P. M. Shand, J. G. Bohnet, J. Goertzen, J. E. Shield, D. Schmitter et al.
Melt-spun Gd is a structurally inhomogeneous system consisting of crystalline grains with an average size of 243 nm that are separated by an amorphous interphase. This system exhibits a depression of T (289.700.01 K) relative to bulk Gd (293 K). The effective critical exponents (beta=0.3890.017, g ... [Phys. Rev. B 77, 184415 (2008)] published Wed May 14, 2008.

Adaptive nonlocal quasicontinuum for deformations of curved crystalline structures

Jong Youn Park and Seyoung Im
This paper presents an adaptive multiscale simulation of deformations of curved crystalline structures such as carbon nanotubes (CNTs). It is based on quasicontinuum approach, which is a coarse-graining method. For fully nonlocal quasicontinuum, high-order interpolation functions are adopted to loca ... [Phys. Rev. B 77, 184109 (2008)] published Wed May 14, 2008.

Statistical approach to dislocation dynamics: From dislocation correlations to a multiple-slip continuum theory of plasticity

Surachate Limkumnerd and Erik Van der Giessen
Due to recent successes of a statistical-based nonlocal continuum crystal plasticity theory for single-glide in explaining various aspects such as dislocation patterning and size-dependent plasticity, several attempts have been made to extend the theory to describe crystals with multiple-slip system ... [Phys. Rev. B 77, 184111 (2008)] published Wed May 14, 2008.

Critical dynamics in confined systems with quenched random impurities

H. Chamati and E. Korutcheva
We study the critical dynamics of a system confined to a hypercubic geometry with periodic boundary conditions in the presence of quenched short-range correlated impurities. By using the random T model with purely relaxational dynamics (model A) and the renormalization group method in the vicinity o ... [Phys. Rev. B 77, 184416 (2008)] published Wed May 14, 2008.

Spin polarization of the magnetic spiral in NaCu[sub 2]O[sub 2] as seen by nuclear magnetic resonance spectroscopy

A. A. Gippius, A. S. Moskvin, and S.-L. Drechsler
The incommensurate (IC) spin ordering in quasi-one-dimensional edge-shared cuprate NaCuO has been studied by Na nuclear magnetic resonance spectroscopy in an external magnetic field near 6 T applied along the main crystallographic axes. The NMR line shape evolution above and below T[approximate]12 ... [Phys. Rev. B 77, 180403 (2008)] published Wed May 14, 2008.

Thermodynamics of the quantum Ising model in the two-dimensional kagome lattice

Chyh-Hong Chern and Mitsuaki Tsukamoto
In the classical Ising model on the kagome lattice, there are macroscopically degenerate classical states with exponentially decayed spin correlation. As the singular quantum perturbation is introduced by applying the transverse magnetic field, the quantum ground state remains disordered, dubbed by ... [Phys. Rev. B 77, 172404 (2008)] published Wed May 14, 2008.

Induced triplet pairing in clean s-wave superconductor/ferromagnet layered structures

Klaus Halterman, Oriol T. Valls, and Paul H. Barsic
We study induced triplet pairing correlations in clean ferromagnet/superconductor/ferromagnet heterostructures. The pairing state in the superconductor is the conventional singlet s wave, and the angle alpha between the magnetizations of the two ferromagnetic layers is arbitrary. We use a numerical ... [Phys. Rev. B 77, 174511 (2008)] published Wed May 14, 2008.

Coordination defects in bismuth-modified arsenic selenide glasses: High-resolution x-ray photoelectron spectroscopy measurements

Roman Golovchak, Oleh Shpotyuk, Andriy Kovalskiy, Alfred C. Miller, Jiri Cech et al.
The possibility of coordination defects formation in Bi-modified chalcogenide glasses is examined by high-resolution x-ray photoelectron spectroscopy. The results provide evidence for the formation of positively charged fourfold coordinated defects on As and Bi sites in glasses with low Bi concentra ... [Phys. Rev. B 77, 172201 (2008)] published Wed May 14, 2008.

Boron carbides formed by coevaporation of B and C atoms: Vapor reactivity, B[sub x]C[sub 1 - x] composition, and bonding structure

I. Caretti, R. Gago, J. M. Albella, and I. Jimenez
Boron carbides (BC) in thin film form have been synthesized in a high vacuum by coevaporation of B and C atoms from independent sources, allowing a study of the whole composition range from pure B films to pure C films. The relationship between the impinging B/C atomic fluxes and the film compositio ... [Phys. Rev. B 77, 174109 (2008)] published Wed May 14, 2008.

Temperature-driven refacetting phase transition in Pb chains on Si(557)

M. Czubanowski, A. Schuster, H. Pfnur, and C. Tegenkamp
By using quantitative low energy electron diffraction, we have studied the temperature-driven phase transition of Pb chains grown on Si(557) substrates at a surface concentration of 1.3 ML. This concentration, which is still below one physical monolayer, exhibits a unique switching of electrical con ... [Phys. Rev. B 77, 174108 (2008)] published Tue May 13, 2008.

Anisotropic magnetization studies of R[sub 2]CoGa[sub 8] single crystals (R = Gd, Tb, Dy, Ho, Er, Tm, Y, and Lu)

Devang A. Joshi, R. Nagalakshmi, S. K. Dhar, and A. Thamizhavel
Single crystals of RCoGa series of compounds were grown by high temperature solution growth (flux) method. These compounds crystallize in a tetragonal crystal structure with the space group P4/mmm. It has been found that RCoGa phase only forms with the heavier rare earths, starting from Gd with a re ... [Phys. Rev. B 77, 174420 (2008)] published Tue May 13, 2008.

How to enhance dephasing time in superconducting qubits

Lukasz Cywinski, Roman M. Lutchyn, Cody P. Nave, and S. Das Sarma
We theoretically investigate the influence of designed pulse sequences in restoring quantum coherence lost due to background noise in superconducting qubits. We consider both 1/f noise and random telegraph noise and show that the qubit coherence time can be substantially enhanced by carefully engine ... [Phys. Rev. B 77, 174509 (2008)] published Tue May 13, 2008.

Spin-chain magnetism in Eu-doped Ca[sub 3]Co[sub 2]O[sub 6] and Ca[sub 3]CoRhO[sub 6] investigated by M[o-umlaut]ssbauer spectroscopy

P. L. Paulose, Niharika Mohapatra, and E. V. Sampathkumaran
We report the results of Eu Mossbauer effect and magnetization measurements in the Eu-doped CaCoO and CaCoRhO, which are of great current interest in the fields of spin-chain magnetism and geometrical frustration. We find that there is a pronounced increase in the linewidth of the Mossbauer spectra ... [Phys. Rev. B 77, 172403 (2008)] published Tue May 13, 2008.

Field dependence of magnetic correlations through the polarization flop transition in multiferroic TbMnO[sub 3]: Evidence for a magnetic memory effect

D. Senff, P. Link, N. Aliouane, D. N. Argyriou, and M. Braden
The field-induced multiferroic transition in TbMnO has been studied by neutron scattering. Apart from strong hysteresis, the magnetic transition associated with the flop of electronic polarization exhibits a memory effect: after a field sweep, TbMnO does not exhibit the same phase as that obtained b ... [Phys. Rev. B 77, 174419 (2008)] published Tue May 13, 2008.

Transmission and reflection of phonons and rotons at the superfluid helium-solid interface

I. N. Adamenko, K. E. Nemchenko, and I. V. Tanatarov
We solve the problem of the transmission and reflection of phonons and rotons at the interface between superfluid helium and a solid for all angles of incidence and in both directions. A consistent solution of the problem is presented, which allows us to rigorously describe the simultaneous creation ... [Phys. Rev. B 77, 174510 (2008)] published Tue May 13, 2008.

Isostructural transitions in bcc Zr induced by the peculiarities of the lattice dynamics under pressure

V. Yu. Trubitsin and E. B. Dolgusheva
The peculiarities of the atomic displacements corresponding to the longitudinal and transverse vibrations with wave vector k=(2/3)[111] in bcc zirconium are considered. It is shown that the three parts, which substantially differ in the lattice dynamics character, can be separated out in the region ... [Phys. Rev. B 77, 172302 (2008)] published Tue May 13, 2008.

Evolution of atomic and electronic structure of Pt clusters: Planar, layered, pyramidal, cage, cubic, and octahedral growth

Vijay Kumar and Yoshiyuki Kawazoe
Ab initio calculations on Pt clusters having diameters of up to about 3 nm show planar, layered, pyramidal, cage, simple cubic, and octahedral growth. Planar structures are preferred up to Pt, while layered and pyramidal structures are favored in the range of Pt, where n=1020. In some cases, simple ... [Phys. Rev. B 77, 205418 (2008)] published Tue May 13, 2008.

Modeling of three-dimensional photonic crystal lasers in a frequency domain: A scattering matrix solution

Xinhua Hu, Jiangrong Cao, Ming Li, Zhuo Ye, Mamoru Miyawaki et al.
We derive a light-intensity-dependent dielectric constant for a gain medium based on the conventional rate equation model. A scattering-matrix method in conjunction with an efficient iteration procedure is proposed to simulate photonic crystal lasers (PCLs). The light output vs pumping (L-I) curve, ... [Phys. Rev. B 77, 205104 (2008)] published Tue May 13, 2008.

Selective manipulation of stop-bands in multi-component photonic crystals: Opals as an example

M. V. Rybin, A. V. Baryshev, A. B. Khanikaev, M. Inoue, K. B. Samusev et al.
We report on a comprehensive theoretical and experimental study of stop-band switching in photonic crystals. The suggested principles of light control are based on new Bragg diffraction effects discovered in multi-component periodic structures. The described analytical approach allows a detailed stu ... [Phys. Rev. B 77, 205106 (2008)] published Tue May 13, 2008.

Atomic and electronic structures of thallium-based III-V-VI[sub 2] ternary chalcogenides: Ab initio calculations

Khang Hoang and S. D. Mahanti
The atomic and electronic structures of III-V-VI ternary chalcogenides (III=Tl, V=Sb and Bi, and VI=Te, Se, and S) have been studied using ab initio electronic structure calculations. Most of these compounds are found to take rhombohedral structures as their lowest energy structures (except for TlSb ... [Phys. Rev. B 77, 205107 (2008)] published Tue May 13, 2008.

Dynamical-quantum-cluster approach to two-particle correlation functions in the Hubbard model

S. Hochkeppel, F. F. Assaad, and W. Hanke
We investigate the charge- and spin-dynamical structure factors for the two-dimensional one-band Hubbard model in the strong coupling regime within the dynamical cluster approximation (DCA) that is explicitly extended to two-particle response functions. The full irreducible two-particle vertex with ... [Phys. Rev. B 77, 205103 (2008)] published Tue May 13, 2008.

Photoinduced insulator-metal transition in one-dimensional Mott insulators

Akira Takahashi, Hisashi Itoh, and Masaki Aihara
We theoretically investigate the dynamics of insulator-metal transition induced by light-pulse excitation in one-dimensional Mott insulators. We adopt the PariserParrPople model and the pump-probe signal is obtained by numerically calculating the time development of the state excited by light pulse. ... [Phys. Rev. B 77, 205105 (2008)] published Tue May 13, 2008.

Induced decoherence and entanglement by interacting quantum spin baths

Cheng-Yan Lai, Jo-Tzu Hung, Chung-Yu Mou, and Pochung Chen
The reduced dynamics of a single qubit or two qubits coupled to an interacting quantum spin bath modeled by an XXZ spin chain is investigated. By using the method of a time-dependent density matrix renormalization group (t-DMRG), we go beyond the uniform coupling central spin model and nonperturbati ... [Phys. Rev. B 77, 205419 (2008)] published Tue May 13, 2008.

Molecular charge distribution and dispersion of electronic states in the contact layer between pentacene and Cu(119) and beyond

E. Annese, J. Fujii, C. Baldacchini, B. Zhou, C. E. Viol et al.
The interaction of pentacene molecules in contact with the Cu(119) stepped surface has been directly imaged by scanning tunneling microscopy and analyzed by angle resolved photoemission spectroscopy. Interacting molecules, which are in contact with copper, generate dispersive electronic states assoc ... [Phys. Rev. B 77, 205417 (2008)] published Tue May 13, 2008.

Effect of screening long-range Coulomb interactions on the metallic behavior in two-dimensional hole systems

L. H. Ho, W. R. Clarke, A. P. Micolich, R. Danneau, O. Klochan et al.
We have developed a technique utilizing a double quantum well heterostructure that allows us to study the effect of a nearby ground plane on the metallic behavior in a GaAs two-dimensional hole system (2DHS) in a single sample and measurement cooldown, thereby maintaining a constant disorder potenti ... [Phys. Rev. B 77, 201402 (2008)] published Tue May 13, 2008.

Double quantum dot as detector of spin bias

Qing-feng Sun, Yanxia Xing, and Shun-Qing Shen
It was proposed that a double quantum dot can be used as a detector of the spin bias. Electron transport through a double quantum dot is theoretically investigated when a pure spin bias is applied on two conducting leads in contact with the quantum dot. It is found that the spin polarization in the ... [Phys. Rev. B 77, 195313 (2008)] published Tue May 13, 2008.

Substrate-limited electron dynamics in graphene

S. Fratini and F. Guinea
We study the effects of polarizable substrates such as SiO and SiC on the carrier dynamics in graphene. We find that the quasiparticle spectrum acquires a finite broadening due to the long-range interaction with the polar modes at the interface between graphene and the substrate. This mechanism resu ... [Phys. Rev. B 77, 195415 (2008)] published Tue May 13, 2008.

Tunneling through molecules and quantum dots: Master-equation approaches

Carsten Timm
An important class of approaches to the description of electronic transport through molecules and quantum dots is based on the master equation. We discuss various formalisms for deriving a master equation and their interrelations. It is shown that the master equation derived by Konig et al. [Phys. R ... [Phys. Rev. B 77, 195416 (2008)] published Tue May 13, 2008.

Electron and spin transport in the presence of a complex absorbing potential

Fatih Dogan, Wonkee Kim, C. M. Blois, and F. Marsiglio
We examine the impact of a complex absorbing potential on electron transport both in the continuum and on a lattice. This requires the use of non-Hermitian Hamiltonians; the required formalism is briefly outlined. The lattice formulation allows us to study the interesting problem of an electron inte ... [Phys. Rev. B 77, 195107 (2008)] published Tue May 13, 2008.

Size-dependent modifications of the first-order Raman spectra of nanostructured rutile TiO[sub 2]

Varghese Swamy
The crystallite-size-dependent Raman spectral modifications observed for a suite of rutile TiO nanocrystals are analyzed and compared to the characteristics of the Raman spectra that were reported for nanoscale rutile TiO domains/crystallites embedded in thin films. The strong E and A modes display ... [Phys. Rev. B 77, 195414 (2008)] published Tue May 13, 2008.

Luttinger liquid fixed point for a two-dimensional flat Fermi surface

Vieri Mastropietro
We consider a system of two-dimensional interacting fermions with a flat Fermi surface. The apparent conflict between Luttinger and non-Luttinger liquid behaviors found through different approximations is resolved by showing the existence of a line of nontrivial fixed points, for the renormalization ... [Phys. Rev. B 77, 195106 (2008)] published Tue May 13, 2008.

Path-integral ground-state Monte Carlo study of two-dimensional solid [sup 4]He

E. Vitali, M. Rossi, F. Tramonto, D. E. Galli, and L. Reatto
We have studied a two-dimensional (2D) triangular commensurate crystal of He with the exact T=0 K path-integral ground-state (PIGS) Monte Carlo method. We have projected onto the true ground state two qualitatively different wave functions, a Jastrow-Nosanow wave function and a translationally inva ... [Phys. Rev. B 77, 180505 (2008)] published Tue May 13, 2008.

Out-of-plane magnetic domain structure in a thin film of La[sub 0.67]Sr[sub 0.33]MnO[sub 3] on SrTiO[sub 3] (001) observed by magnetic force microscopy

E. P. Houwman, G. Maris, G. M. De Luca, N. Niermann, G. Rijnders et al.
The room temperature out-of-plane magnetization of epitaxial thin films of LaSrMnO on SrTiO (001) has been investigated with magnetic force microscopy, using magnetic tips with very small coercivity, relative to the film. A clear magnetic pattern in the form of a checkerboard, with domain dimensions ... [Phys. Rev. B 77, 184412 (2008)] published Tue May 13, 2008.

Melting of magnetic correlations in charge-orbital ordered La[sub 1/2]Sr[sub 3/2]MnO[sub 4]: Competition of ferromagnetic and antiferromagnetic states

D. Senff, O. Schumann, M. Benomar, M. Kriener, T. Lorenz et al.
The magnetic correlations in the charge and orbital ordered manganite LaSrMnO have been studied by elastic and inelastic neutron scattering techniques. Out of the well-defined charge exchange (CE)-type magnetic structure with the corresponding magnons, a competition between CE-type and ferromagnetic ... [Phys. Rev. B 77, 184413 (2008)] published Tue May 13, 2008.

Correlation effects in the electronic structure of the Mn[sub 4] molecular magnet

D. W. Boukhvalov, L. I. Vergara, V. V. Dobrovitski, M. I. Katsnelson, A. I. Lichtenstein et al.
We present joint theoretical-experimental study of correlation effects in the electronic structure of (pyH)[MnOCl(OAc)]2MeCN molecular magnet (Mn). Describing the many-body effects by cluster dynamical mean-field theory, we find that Mn is predominantly a Hubbard insulator with strong electron corre ... [Phys. Rev. B 77, 180402 (2008)] published Tue May 13, 2008.

Molecular dynamics investigation of dynamical heterogeneity and local structure in the supercooled liquid and glass states of Al

Maozhi Li, Cai-Zhuang Wang, Mikhail I. Mendelev, and Kai-Ming Ho
Molecular dynamics simulations are performed to study the structure and dynamical heterogeneity in the liquid and glass states of Al using a frequently employed embedded atom potential. While the pair correlation function of the glass and liquid states displays only minor differences, the icosahedra ... [Phys. Rev. B 77, 184202 (2008)] published Tue May 13, 2008.

Effect of oxygen-doping on Bi[sub 2]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub 10 + delta] vortex matter: Crossover from electromagnetic to Josephson interlayer coupling

A. Piriou, Y. Fasano, E. Giannini, and O. Fischer
We study the effect of oxygen-doping on the critical temperature T, the vortex matter phase diagram, and the nature of the coupling mechanism between the Cu-O layers in the three-layer BiSrCaCuO (Bi-2223) compound. Contrary to previous reports, in the overdoped (OD) regime, we do find a variation in ... [Phys. Rev. B 77, 184508 (2008)] published Tue May 13, 2008.

Probing non-Abelian statistics in nu = 12/5 quantum Hall state

K. T. Law
The tunneling current and shot noise of the current between two fractional quantum hall (FQH) edges in the nu=12/5 FQH state in an electronic MachZehnder interferometer are studied. It is shown that the tunneling current and shot noise can be used to probe the existence of k=3 parafermion statistics ... [Phys. Rev. B 77, 205310 (2008)] published Mon May 12, 2008.

Theory of the valley-valve effect in graphene nanoribbons

A. R. Akhmerov, J. H. Bardarson, A. Rycerz, and C. W. J. Beenakker
A potential step in a graphene nanoribbon with zigzag edges is shown to be an intrinsic source of intervalley scatteringno matter how smooth the step is on the scale of the lattice constant a. The valleys are coupled by a pair of localized states at the opposite edges, which act as an attractor and/ ... [Phys. Rev. B 77, 205416 (2008)] published Mon May 12, 2008.

Influence of the shape and size of a quantum wire on the trion binding energy

Y. Sidor, B. Partoens, and F. M. Peeters
The binding energy for charged excitons (X and X) is calculated within the single-band effective mass approximation including effects due to strain for rectangular, triangular, and V-shaped quantum wires. Both X and X are found to be bound in rectangular InAs/InP quantum wires and V-shaped GaAs/AlGa ... [Phys. Rev. B 77, 205413 (2008)] published Mon May 12, 2008.

In situ real-time investigation of kinetics of nucleation and growth of sol-gel-derived functional oxide thin films

Tao Sun, Hao Hu, Zixiao Pan, Xuefa Li, Jin Wang et al.
Early-stage nucleation and growth kinetics of sol-gel-derived multiferroic BiFeO thin films were investigated in situ and in real time by combining transmission electron microscopy and grazing-incidence small-angle x-ray scattering (GISAXS). While the initial phase of the nuclei was identified to be ... [Phys. Rev. B 77, 205414 (2008)] published Mon May 12, 2008.

Low temperature electron-phonon resonance in dc-current-biased two-dimensional electron systems

X. L. Lei
Effects of resonant acoustic phonon scattering on magnetoresistivity are examined in two-dimensional electron systems at low temperatures by using a balance-equation magnetotransport scheme directly controlled by the current. The experimentally observed resonances in linear resistivity are shown to ... [Phys. Rev. B 77, 205309 (2008)] published Mon May 12, 2008.

Resonant magnetopolaron effect in a high electron density quantum well in a tilted magnetic field

S. N. Klimin, V. M. Fomin, and J. T. Devreese
The cyclotron resonance (CR) spectra are calculated for a high electron density GaAs/AlAs quantum well in a tilted magnetic field. The CR peaks are split due to (i) the resonant magnetopolaron effect and (ii) the anticrossing of the CR mode and the plasmon-phonon intersubband modes. The derived CR p ... [Phys. Rev. B 77, 205311 (2008)] published Mon May 12, 2008.

Disappearance of the quasi-one-dimensional plasmon at the metal-insulator phase transition of indium atomic wires

Canhua Liu, Takeshi Inaoka, Shin Yaginuma, Tomonobu Nakayama, Masakazu Aono et al.
An array of indium atomic wires on Si(111) exhibits a temperature-induced phase transition between (4 x 1) and (8 x 2) structures, both of which were investigated by using electron energy loss spectroscopy (EELS). The EELS spectra of the (4 x 1) phase taken at room temperature show a clear momentum- ... [Phys. Rev. B 77, 205415 (2008)] published Mon May 12, 2008.

Formation of silicon-fullerene-linked nanowires inside carbon nanotubes: A molecular-dynamics and first-principles study

Kengo Nishio, Taisuke Ozaki, Tetsuya Morishita, and Masuhiro Mikami
We study the formation of Si nanowires inside carbon nanotubes by using a combination of empirical molecular-dynamics and first-principles approaches. Molecular-dynamics simulations demonstrate that liquid Si encapsulated into a (13,0) nanotube crystallizes into a nanowire composed of linked Si full ... [Phys. Rev. B 77, 201401 (2008)] published Mon May 12, 2008.

Effects of interaction-induced second Landau level mixing in the nu = 1 quantum Hall effect

Mats Horsdal
The work by Mandal and Jain [Solid State Commun. 118, 503 (2001)] suggests that interaction-induced mixing with the second composite fermion Landau level can lead to renormalization of the electron correlation function exponent in the fractional quantum Hall effect. In the work reported here, a simi ... [Phys. Rev. B 77, 195312 (2008)] published Mon May 12, 2008.

Relaxation of electron-hole pairs by coherent emission of LO-phonons in the quantum kinetic regime measured in CdZnTe quantum wells

S. Cronenberger, C. Brimont, O. Cregut, K. Kheng, H. Mariette et al.
We study the relaxation of excitons in CdZnTe quantum wells by emission of a LO-phonon cascade, ending with a trapping in quantum dots. The state filling of the dots is measured in two-color pump-probe experiments. The observed optical-phonon emission time is found to be smaller (130 fs) than the ph ... [Phys. Rev. B 77, 195311 (2008)] published Mon May 12, 2008.

Suppressing charge noise decoherence in superconducting charge qubits

J. A. Schreier, A. A. Houck, Jens Koch, D. I. Schuster, B. R. Johnson et al.
We present an experimental realization of the transmon qubit, which is an improved superconducting charge qubit derived from the Cooper pair box. We experimentally verify the predicted exponential suppression of sensitivity to 1/f charge noise. This removes the leading source of dephasing in charge ... [Phys. Rev. B 77, 180502 (2008)] published Mon May 12, 2008.

Single-ion and exchange anisotropy effects and multiferroic behavior in high-symmetry tetramer single-molecule magnets

Richard A. Klemm and Dmitri V. Efremov
We study single-ion and exchange anisotropy effects in equal-spin s tetramer single-molecule magnets exhibiting T, D, D, C, C, or S ionic site point group symmetry. We first write the group-invariant quadratic single-ion and symmetric anisotropic exchange Hamiltonians in the appropriate local coordi ... [Phys. Rev. B 77, 184410 (2008)] published Mon May 12, 2008.

Superconductivity in the actinoid-bearing filled skutterudite ThPt[sub 4]Ge[sub 12]

D. Kaczorowski and V. H. Tran
ThPtGe is an actinoid-bearing representative of a recently discovered family of Ge-based skutterudites. Based on magnetization, electrical resistivity, and specific heat data, the compound was characterized as a clean-limit strong-coupling superconductor with T=4.62 K. Moreover, some hints are give ... [Phys. Rev. B 77, 180504 (2008)] published Mon May 12, 2008.

Melting and freezing of embedded nanoclusters

Frederic Caupin
Small crystals are known to melt at a different temperature than the bulk; it is usually lower for freestanding nanocrystals. However, the size-dependent melting temperature is often analyzed with approximate formulas, corresponding to the limits of metastability of the solid cluster, instead of acc ... [Phys. Rev. B 77, 184108 (2008)] published Mon May 12, 2008.

Excitation of coupled oscillations in lateral ferromagnetic heterostructures

Nikolay I. Polushkin
The intensities of spin-wave (magnetostatic) modes in thin ferromagnetic films and laterally confined structures are usually insensitive to their dimensions. We observe a strong dependence of the resonant microwave absorption in periodic heterostructures of closely packed ferromagnetic stripes on th ... [Phys. Rev. B 77, 180401 (2008)] published Mon May 12, 2008.

Crossover in the local density of states of mesoscopic superconductor/normal-metal/superconductor junctions

Alex Levchenko
Andreev levels deplete energy states above the superconductive gap, which leads to the peculiar nonmonotonous crossover in the local density of states of mesoscopic superconductor/normal-metal/superconductor junctions. This effect is especially pronounced in the case when the normal metal bridge len ... [Phys. Rev. B 77, 180503 (2008)] published Mon May 12, 2008.

Magnetocaloric and magnetotransport properties of R[sub 2]Ni[sub 2]Sn compounds (R = Ce, Nd, Sm, Gd, and Tb)

Pramod Kumar, Niraj K. Singh, K. G. Suresh, and A. K. Nigam
We report a detailed magnetic, magnetocaloric, and magnetotransport study on RNiSn compounds with different rare earths. The magnetic state of these compounds is found to be complex because of the coexistence of ferromagnetic and antiferromagnetic components. These compounds show phenomena such as m ... [Phys. Rev. B 77, 184411 (2008)] published Mon May 12, 2008.

Twisted magnetization state at the interface of an antiferromagnetically coupled Fe/Si multilayer as probed by specular and off-specular polarized neutron scattering

Amitesh Paul, Matthias Buchmeier, Daniel E. Burgler, Ulrich Rucker, and Claus M. Schneider
We have investigated strongly coupled Fe/Si multilayers by polarized neutron scattering in specular and off-specular modes. By using the specular reflectivity patterns as a function of the applied field, we have extracted the magnetization angles for layers buried in the stack. In order to explore t ... [Phys. Rev. B 77, 184409 (2008)] published Mon May 12, 2008.

Relationship between ferroelectricity and Dzyaloshinskii-Moriya interaction in multiferroics and the effect of bond-bending

C. D. Hu
We studied the microscopic mechanism of multiferroics, in particular, with the spin current model [H. Katsura et al., Phys. Rev. Lett. 95, 057205 (2005)]. Starting from a system with helical spin configuration, we solved for the forms of the electron wave functions and analyzed their characteristics ... [Phys. Rev. B 77, 174418 (2008)] published Mon May 12, 2008.

Motion of a spherical solid particle in thermal counterflow turbulence

Demosthenes Kivotides
With numerical methods, we formulate and solve a mathematical model of solid-particle motion in thermal counterflow turbulence. We find a direct link between the intensity of vortex-particle collision induced Kelvin waves (vortex-gas temperature) and the intensity of the particle-velocity fluctuatio ... [Phys. Rev. B 77, 174508 (2008)] published Mon May 12, 2008.

Normal-state transport in electron-doped La[sub 2 - x]Ce[sub x]CuO[sub 4] thin films in magnetic fields up to 40 Tesla

K. Jin, B. Y. Zhu, B. X. Wu, J. Vanacken, V. V. Moshchalkov et al.
The in-plane normal-state transport properties of electron-doped superconductor (LaCe)CuO (LCCO) thin films with 0.06<=x<=0.17 are studied in magnetic fields up to 40 Tesla. For the whole doping region investigated, the negative magnetoresistivity (n-MR) is found below certain temperatures, with mi ... [Phys. Rev. B 77, 172503 (2008)] published Mon May 12, 2008.

Identifying the odd-frequency pairing state of superconductors by a field-induced Josephson effect

Jacob Linder, Takehito Yokoyama, and Asle Sudbo
Superconducting order parameters that are odd under exchange of time coordinates of the electrons constituting a Cooper pair are potentially of great importance both conceptually and technologically. Recent experiments report that such an odd-frequency superconducting bulk state may be realized in c ... [Phys. Rev. B 77, 174507 (2008)] published Mon May 12, 2008.

Effect of magnetic field and temperature on the ferroelectric loop in[bold ]MnWO[sub 4]

Bohdan Kundys, Charles Simon, and Christine Martin
The ferroelectric properties of MnWO single crystal have been investigated. Despite a relatively low remanent polarization, we show that the sample is ferroelectric. The shape of the ferroelectric loop of MnWO strongly depends on magnetic field and temperature. While its dependence does not directly ... [Phys. Rev. B 77, 172402 (2008)] published Mon May 12, 2008.

Linewidth of resonances in scanning tunneling spectroscopy

L. Jdira, K. Overgaag, R. Stiufiuc, B. Grandidier, C. Delerue et al.
Cryogenic scanning tunneling spectroscopy is increasingly used to study the electronic structure of adatoms, molecules, and semiconductor quantum dots. However, the width of the conductance resonances that indicate the energy levels is much larger than the thermal energy, and this is not well unders ... [Phys. Rev. B 77, 205308 (2008)] published Fri May 9, 2008.

Erratum: Analysis of vector potential approach for calculating linear and nonlinear responses of infinite periodic systems to a finite static external electric field [Phys. Rev. B [bold 77], 045102 (2008)]

Michael Springborg and Bernard Kirtman
... [Phys. Rev. B 77, 209901 (2008)] published Fri May 9, 2008.

Epitaxial growth and quantum well states study of Sn thin films on Sn induced Si(111)-(2sqrt(3) x 2sqrt(3)) R30[degree] surface

L. L. Wang, X. C. Ma, S. H. Ji, Y. S. Fu, Q. T. Shen et al.
Surface morphologies and electronic structures of Sn thin films prepared on Si(111)-Sn(2sqrt(3) x 2sqrt(3)) R30 degrees substrate are investigated by low temperature scanning tunneling microscopy/scanning tunneling spectroscopy (STS). A typical StranskiKrastanov growth is observed at various growth ... [Phys. Rev. B 77, 205410 (2008)] published Fri May 9, 2008.

Vacancy-induced magnetism in ZnO thin films and nanowires

Qian Wang, Qiang Sun, Gang Chen, Yoshiyuki Kawazoe, and Puru Jena
Extensive calculations based on density functional theory have been carried out to understand the origin of magnetism in undoped ZnO thin films as found in recent experiments. The observed magnetism is confirmed to be due to Zn, instead of O, vacancy. The main source of the magnetic moment, however, ... [Phys. Rev. B 77, 205411 (2008)] published Fri May 9, 2008.

First principles calculations of the structural and electronic properties of the type-I semiconductor clathrate alloys Ba[sub 8]Ga[sub 16]Si[sub x]Ge[sub 30 - x] and Sr[sub 8]Ga[sub 16]Si[sub x]Ge[sub 30 - x]

Emmanuel N. Nenghabi and Charles W. Myles
We studied the structural and electronic properties of some of the Ba and Sr guest-containing type-I semiconductor clathrate alloys BaGaSiGe and SrGaSiGe for three values of the Si composition x (x=0,5,15). Our calculations are based on the generalized gradient approximation to density functional th ... [Phys. Rev. B 77, 205203 (2008)] published Fri May 9, 2008.

Edge states, mass and spin gaps, and quantum Hall effect in graphene

V. P. Gusynin, V. A. Miransky, S. G. Sharapov, and I. A. Shovkovy
Motivated by recent experiments and a theoretical analysis of the gap equation for the propagator of Dirac quasiparticles, we assume that the physics underlying the recently observed removal of sublattice and spin degeneracies in graphene in a strong magnetic field is connected with the generation o ... [Phys. Rev. B 77, 205409 (2008)] published Fri May 9, 2008.

Vertical manipulation of a molecule with chemical forces

Natalia Martsinovich and Lev Kantorovich
We propose and theoretically discuss a protocol for the vertical manipulation of chemisorbed molecules which does not involve applying large bias voltages and is entirely due to scanning tunneling microscopy tip-molecule covalent interactions: a tip, which strongly interacts with the molecule, bring ... [Phys. Rev. B 77, 205412 (2008)] published Fri May 9, 2008.

Nonequilibrium sum rules for the retarded self-energy of strongly correlated electrons

V. Turkowski and J. K. Freericks
We derive the first two moment sum rules of the conduction electron retarded self-energy for both the FalicovKimball model and the Hubbard model coupled to an external spatially uniform and time-dependent electric field (this derivation also extends the known nonequilibrium moment sum rules for the ... [Phys. Rev. B 77, 205102 (2008)] published Fri May 9, 2008.

Ge-induced (1 x 2) surface reconstruction on GaAs(001): A precursor to As segregation

Akihiro Ohtake, Jun Nara, Tetsuji Yasuda, and Noriyuki Miyata
The initial Ge growth on the GaAs(001) surface has been studied. We found that the initial Ge growth promotes the site exchange between Ge and As atoms, resulting in the formation of surface Ga-As dimers with (1 x 2) periodicity. The proposed structure model was found to be energetically favorable b ... [Phys. Rev. B 77, 195309 (2008)] published Fri May 9, 2008.

Dual fermion approach to susceptibility of correlated lattice fermions

S. Brener, H. Hafermann, A. N. Rubtsov, M. I. Katsnelson, and A. I. Lichtenstein
In this paper, we show how the two-particle Green function can be obtained within the framework of the dual fermion approach. This facilitates the calculation of the susceptibility in strongly correlated systems where long-ranged nonlocal correlations cannot be neglected. We formulate the BetheSalpe ... [Phys. Rev. B 77, 195105 (2008)] published Fri May 9, 2008.

Identification of antisite carbon split-interstitial defects in 4H-SiC

J. W. Steeds and W. Sullivan
A rich variety of optical centers with high energy local vibrational modes has been found in electron-irradiated 4H-SiC in both the as-irradiated and annealed states. These energies have been measured and the annealing dependence of the optical centers has been investigated by low-temperature photol ... [Phys. Rev. B 77, 195204 (2008)] published Fri May 9, 2008.

Graphene via large N: A renormalization group study

Matthew S. Foster and Igor L. Aleiner
We analyze the competing effects of moderate to strong Coulomb electron-electron interactions and weak quenched disorder in graphene. By using a one-loop renormalization group calculation controlled within the large-N approximation, we demonstrate that at successively lower energy (temperature or ch ... [Phys. Rev. B 77, 195413 (2008)] published Fri May 9, 2008.

Adsorption of diatomic molecules on iron tape-porphyrin: A comparative study

Tien Quang Nguyen, Mary Clare Sison Escano, Nobuaki Shimoji, Hiroshi Nakanishi, and Hideaki Kasai
We investigated the adsorption of diatomic molecules, CO, NO, and O, denoted by XO on iron tape-porphyrin (FeTP) using first-principles calculations based on density functional theory. In this work, we present the structure and electronic properties of iron tape-porphyrin and its complexes with CO, ... [Phys. Rev. B 77, 195307 (2008)] published Fri May 9, 2008.

Effect of electron-electron scattering on spin dephasing in a high-mobility low-density two-dimensional electron gas

X. Z. Ruan, H. H. Luo, Yang Ji, Z. Y. Xu, and V. Umansky
By utilizing time-resolved Kerr rotation techniques, we have investigated the spin dynamics of a high-mobility low density two-dimensional electron gas in a GaAs/AlGaAs heterostructure in the dependence on temperature from 1.5 to 30 K. It is found that the spin relaxation/dephasing time under a magn ... [Phys. Rev. B 77, 193307 (2008)] published Fri May 9, 2008.

Creation and identification of the two spin states of dicarbon antisite defects in 4H-SiC

J. W. Steeds, W. Sullivan, S. A. Furkert, G. A. Evans, and P. J. Wellmann
This paper deals with the positive identification by low-temperature photoluminescence microspectroscopy of the two spin states of the dicarbon antisites in 4H-SiC. The defects are created by high-dose electron irradiation at room temperature or by subsequent exposure to intense 325 nm radiation at ... [Phys. Rev. B 77, 195203 (2008)] published Fri May 9, 2008.

Single-particle relaxation time versus transport scattering time in a two-dimensional graphene layer

E. H. Hwang and S. Das Sarma
We theoretically calculate and compare the single particle relaxation time (tau) defining the quantum level broadening and the transport scattering time (tau) defining the Drude conductivity in two-dimensional (2D) graphene layers in the presence of screened charged impurity scattering and short-ran ... [Phys. Rev. B 77, 195412 (2008)] published Fri May 9, 2008.

Barrier height at (Ba,Sr)TiO[sub 3]/Pt interfaces studied by photoemission

R. Schafranek, S. Payan, M. Maglione, and A. Klein
The interface formation of Nb-doped SrTiO single crystals and (Ba,Sr)TiO thin films with Pt has been studied by using photoelectron spectroscopy with in situ sample preparation. For the single crystal sample, a Schottky barrier height for electrons of 0.50.6 eV is determined after deposition of Pt i ... [Phys. Rev. B 77, 195310 (2008)] published Fri May 9, 2008.

Entanglement between remote spin-qubits in one dimension by scattering in the real-space Anderson model

M. Habgood, J. H. Jefferson, and G. A. D. Briggs
The possibility of generating entanglement between two solid-state electron spin-qubits by spin-dependent scattering of a third, propagating electron is attractive. A process of this kind could work well beyond the range of the direct interaction between the two spins. In this study, the binding of ... [Phys. Rev. B 77, 195308 (2008)] published Fri May 9, 2008.

Electrical transport in single-crystalline Li[sub 0.9]Mo[sub 6]O[sub 17]: A two-band Luttinger liquid exhibiting Bose metal behavior

C. A. M. dos Santos, M. S. da Luz, Yi-Kuo Yu, J. J. Neumeier, J. Moreno et al.
Temperature-dependent electrical resistance in quasi-one-dimensional LiMoO is described by two Luttinger liquid anomalous exponents alpha, each associated with a distinct one dimensional band. The band with alpha<1 is argued to crossover to a higher dimension below the temperature T, leading to supe ... [Phys. Rev. B 77, 193106 (2008)] published Fri May 9, 2008.

Multiple elastic scattering of core-loss electrons in atomic resolution imaging

C. Dwyer, S. D. Findlay, and L. J. Allen
We consider the elastic scattering of a fast incident electron both prior and subsequent to its involvement in an atomic inner-shell ionization (core-loss) event in a crystal. By using numerical simulations, it is shown that elastic scattering subsequent to ionization can strongly affect the qualita ... [Phys. Rev. B 77, 184107 (2008)] published Fri May 9, 2008.

Phonon partial densities of states and entropies of Fe and Cr in bcc Fe-Cr from inelastic neutron scattering

Matthew S. Lucas, M. Kresch, R. Stevens, and B. Fultz
Inelastic neutron-scattering spectra were measured on disordered solid solutions of body-centered cubic Fe-Cr alloys of different compositions. These data were reduced from time-of-flight histograms to energy spectra that resemble the phonon density of states (DOS) but were distorted by differences ... [Phys. Rev. B 77, 184303 (2008)] published Fri May 9, 2008.

Manipulation with Andreev states in spin active mesoscopic Josephson junctions

J. Michelsen, V. S. Shumeiko, and G. Wendin
We investigate manipulation with Andreev bound states in Josephson quantum point contacts with magnetic scattering. The Rabi oscillations in the two-level Andreev subsystems are excited by resonant driving the direction of magnetic moment of the scatterer and by modulating the superconducting phase ... [Phys. Rev. B 77, 184506 (2008)] published Fri May 9, 2008.

Contribution of the decay of optical phonons into acoustic phonons to the thermal conductivity of AlN

M. Kazan, S. Pereira, M. R. Correia, and P. Masri
The thermal conductivity along two high-symmetry directions of several aluminum nitride (AlN) single crystals differing in their mass-fluctuation phonon-scattering parameter is described accurately in the full temperature range by taking into account the contribution of optical phonon decay into aco ... [Phys. Rev. B 77, 180302 (2008)] published Fri May 9, 2008.

Thermophysical properties of warm dense hydrogen using quantum molecular dynamics simulations

Bastian Holst, Ronald Redmer, and Michael P. Desjarlais
We study the thermophysical properties of warm dense hydrogen by using quantum molecular dynamics simulations. Results are presented for the pair distribution functions, the equation of state, and the Hugoniot curve. From the dynamic conductivity, we derive the dc electrical conductivity and the ref ... [Phys. Rev. B 77, 184201 (2008)] published Fri May 9, 2008.

Josephson current and multiple Andreev reflections in graphene SNS junctions

Xu Du, Ivan Skachko, and Eva Y. Andrei
The Josephson effect and superconducting proximity effect were observed in superconductor-graphene-superconductor (SGS) Josephson junctions with coherence lengths comparable to the distance between the superconducting leads. By comparing the measured gate dependence of the proximity induced subgap f ... [Phys. Rev. B 77, 184507 (2008)] published Fri May 9, 2008.

Crystal and magnetic structures of NdBaCo[sub 2]O[sub 5 + delta] (delta ~ 0.75): A neutron diffraction study

D. D. Khalyavin, O. Prokhnenko, N. Stusser, V. Sikolenko, V. Efimov et al.
The crystal structure and magnetic ordering in NdBaCoO cobaltites have been studied by neutron powder diffraction. A successful refinement of the high temperature paramagnetic patterns for both as-prepared (delta~0.71) and oxidized (delta~0.75) compositions was performed in the Pmmm space group with ... [Phys. Rev. B 77, 174417 (2008)] published Fri May 9, 2008.

Calculation of Chern number spin Hamiltonians for magnetic nano-clusters by DFT methods

T. O. Strandberg, C. M. Canali, and A. H. MacDonald
By combining field-theoretical methods and ab initio calculations, we construct an effective Hamiltonian with a single giant-spin degree of freedom, which is capable of describing the low-energy spin dynamics of ferromagnetic metal nano-clusters consisting of up to a few tens of atoms. In our proced ... [Phys. Rev. B 77, 174416 (2008)] published Fri May 9, 2008.

Preparation and properties of amorphous MgB[sub 2]/MgO superstructures: Model disordered superconductor

W. Siemons, M. A. Steiner, G. Koster, D. H. A. Blank, M. R. Beasley et al.
In this paper, we introduce a unique method for fabricating MgB/MgO multilayers and demonstrate the potential for using them as a new model for disordered superconductors. In this approach, we control the annealing of the MgB to yield an interesting new class of disordered (amorphous) superconductor ... [Phys. Rev. B 77, 174506 (2008)] published Fri May 9, 2008.

Canted stripe phase near the spin reorientation transition in ultrathin magnetic films

J. P. Whitehead, A. B. MacIsaac, and K. De'Bell
Results from computer simulation and numerical studies for the ferromagnetic Heisenberg model on a square lattice are presented. The model includes the exchange and dipolar interactions as well as the magnetic anisotropy. The analysis focuses on the nature of the stripe phase which determines the ph ... [Phys. Rev. B 77, 174415 (2008)] published Fri May 9, 2008.

Upper bounds on the Witten index for supersymmetric lattice models by discrete Morse theory. (arXiv:0805.2163v1 [cond-mat.str-el])

ePrint arXiv http://arXiv.org/

Three-Dimensional Percolation Modeling of Self-Healing Composites. (arXiv:0805.2188v1 [cond-mat.mtrl-sci])

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Role of the Majorana Fermion and the Edge Mode in Chiral Superfluidity near a p-Wave Feshbach Resonance. (arXiv:0805.2204v1 [cond-mat.supr-con])

ePrint arXiv http://arXiv.org/

Chirality-Selective Excitation of Coherent Phonons in Carbon Nanotubes. (arXiv:0805.2206v1 [cond-mat.mtrl-sci])

ePrint arXiv http://arXiv.org/

Dynamical Casimir effect for magnons in a spinor Bose-Einstein condensate. (arXiv:0805.2210v1 [cond-mat.other])

ePrint arXiv http://arXiv.org/

Weakly disordered absorbing-state phase transitions. (arXiv:0805.2211v1 [cond-mat.stat-mech])

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Evidence of valence band perturbations in GaAsN/GaAs(001): A combined variable-angle spectroscopic ellipsometry and modulated photoreflectance investigation. (arXiv:0805.2212v1 [cond-mat.mtrl-sci])

ePrint arXiv http://arXiv.org/

Monovacancy-induced magnetism in graphene bilayers. (arXiv:0805.2213v1 [cond-mat.other])

ePrint arXiv http://arXiv.org/

Field-induced quantum critical route to a Fermi liquid in high-temperature superconductors. (arXiv:0805.2215v1 [cond-mat.supr-con])

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MuSR studies of RE(O,F)FeAs (RE = La, Nd, Ce) and LaOFeP systems: possible incommensurate/stripe magnetism and superfluid density. (arXiv:0805.2186v1 [cond-mat.supr-con])

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Persistent Spin Dynamics in the $S=1/2$ V$_{15}$ Molecular Nano-Magnet. (arXiv:0805.2164v1 [cond-mat.mes-hall])

ePrint arXiv http://arXiv.org/

Theory of the Magnetic Moment in Iron Pnictides. (arXiv:0805.2167v1 [cond-mat.str-el])

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