Electronic Structure And Transport

Electrically Driven Spin Dynamics of Paramagnetic Impurities

D. Saha, L. Siddiqui, P. Bhattacharya, S. Datta, D. Basu et al.
The spin dynamics of dilute paramagnetic impurities embedded in a semiconductor GaAs channel of a conventional lateral spin valve has been investigated. It is observed that the electron spin of paramagnetic Mn atoms can be polarized electrically when driven by a spin valve in the antiparallel config ... [Phys. Rev. Lett. 100, 196603 (2008)] published Fri May 16, 2008.

Electronic and Structural Origin of Ultraincompressibility of 5d Transition-Metal Diborides MB[sub 2] (M = W, Re, Os)

Xing-Qiu Chen, C. L. Fu, M. KrCmar, and G. S. Painter
First-principles theory was used to investigate the roles of bond topology and covalency in the phase stability and elastic strength of 5d transition-metal diborides, focusing on elements (M=W, Re, Os) that have among the lowest compressibilities of all metals. Among the phases studied, the ReB-type ... [Phys. Rev. Lett. 100, 196403 (2008)] published Fri May 16, 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.

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.

Probing the band structure of InAs/GaAs quantum dots by capacitance-voltage and photoluminescence spectroscopy

W. Lei, M. Offer, A. Lorke, C. Notthoff, C. Meier et al.
The band structure of self-assembled InAs quantum dots, embedded in a GaAs matrix, is probed with capacitance-voltage spectroscopy and photoluminescence (PL) spectroscopy. The electron energy levels in the quantum dots with respect to the electron ground state of the wetting layer (WL) are determine ... [Appl. Phys. Lett. 92, 193111 (2008)] published Thu May 15, 2008.

Spin-dependent density of states in Ga[sub 1 - x]Mn[sub x]As probed by tunneling spectroscopy

H. Saito, A. Yamamoto, S. Yuasa, and K. Ando
We conducted spin-dependent tunneling spectroscopy measurements in Fe/ZnSe/GaMnAs magnetic tunnel diodes that had a metal-insulator-semiconductor structure. The tunneling magnetoresistance signal in differential conductance spectra (dI/dVV) was found to disappear for bias voltages (V) higher than 35 ... [Appl. Phys. Lett. 92, 192512 (2008)] published Thu May 15, 2008.

Giant positive magnetoresistance in Co-doped ZnO nanocluster films

Y. F. Tian, J. Antony, R. Souza, S. S. Yan, L. M. Mei et al.
We have studied nanostructures and magnetoresistance of 0.5%, 12%, and 30% Co-doped ZnO nanocluster films which were deposited by a third generation sputtering-gas-aggregation source on Si wafer. Microstructure analysis is performed by x-ray photoelectron spectrometer, transmission electron microsco ... [Appl. Phys. Lett. 92, 192109 (2008)] published Thu May 15, 2008.

Polarity dependent breakdown of the high-kappa /SiO[sub x] gate stack: A phenomenological explanation by scanning tunneling microscopy

D. S. Ang, Y. C. Ong, S. J. O'Shea, K. L. Pey, C. H. Tung et al.
From scanning tunneling microscopy, we present unambiguous evidence of thermally induced localized conduction paths exhibiting an asymmetrical conduction property in the high-kappa gate stack. The tunneling current under gate injection biasing is found to be much larger than that under substrate inj ... [Appl. Phys. Lett. 92, 192904 (2008)] published Thu May 15, 2008.

Lifetime and diffusion length of photogenerated minority carriers in single-crystalline n-type beta-FeSi[sub 2] bulk

Teruhisa Ootsuka, Takashi Suemasu, Jun Chen, Takashi Sekiguchi, and Yoshiaki Hara
We have evaluated the lifetime and diffusion length of photogenerated minority carriers (holes) in single-crystalline n-type beta-FeSi bulk grown by chemical vapor transport. The diffusion length measured by optical-beam-induced current agreed well with that measured by electron-beam-induced current ... [Appl. Phys. Lett. 92, 192114 (2008)] published Thu May 15, 2008.

Effect of frequency and temperature on microwave-induced magnetoresistance oscillations in two-dimensional electron systems

Jesus Inarrea
Experimental results on microwave-induced magnetoresistance oscillations in two-dimensional electron systems show a similar behavior regarding temperature and microwave frequency. It is found that these oscillations tend to quench when frequency or temperature increases, approaching magnetoresistanc ... [Appl. Phys. Lett. 92, 192113 (2008)] published Thu May 15, 2008.

Modification of the electronic structure in a carbon nanotube with the charge dopant encapsulation

Woon Ih Choi, Jisoon Ihm, and Gunn Kim
We present the first-principles study of effects of the charge dopants such as cesium and iodine encapsulated on the electronic structure of carbon nanotubes (CNTs). An encapsulated cesium atom donates an electron to the nanotube and produces donorlike states below the conduction bands. In contrast, ... [Appl. Phys. Lett. 92, 193110 (2008)] published Thu May 15, 2008.

Thermal conductivity reduction in oxygen-deficient strontium titanates

Choongho Yu, Matthew L. Scullin, Mark Huijben, Ramamoorthy Ramesh, and Arun Majumdar
We report significant thermal conductivity reduction in oxygen-deficient lanthanum-doped strontium titanate (SrLaTiO) films as compared to unreduced strontium titanates. Our experimental results suggest that the oxygen vacancies could have played an important role in the reduction. This could be due ... [Appl. Phys. Lett. 92, 191911 (2008)] published Thu May 15, 2008.

Electronic and magnetic properties of armchair and zigzag graphene nanoribbons

Frank J. Owens
The electronic properties, band gap, and ionization potential of zigzag and armchair graphene nanoribbons are calculated as a function of the number of carbon atoms in the ribbon employing density functional theory at the B3LYP/6-31G level. In armchair ribbons, the ionization potential and band gap ... [J. Chem. Phys. 128, 194701 (2008)] published Thu May 15, 2008.

Charge Transfer across a ZnO/Electrolyte Interface Induced by Sub-Bandgap Illumination: Role of the Surface States

Liudmila Larina, Edward M. Trukhan, Oleg Shevaleevskiy, and Byung Tae Ahn
The role of interfacial bandgap states in sub-bandgap photoinduced electron transfer across a ZnO/electrolyte junction has been analyzed using time-resolved photocurrent measurements in the millisecond regime. The crystallographic structure and morphology of ZnO samples were characterized using X-ra ... [J. Electrochem. Soc. 155, H529 (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.

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.

Exact Solution for Hopping Dissociation of Geminate Electron-Hole Pairs in a Disordered Chain

O. Rubel, S. D. Baranovskii, W. Stolz, and F. Gebhard
A universal theoretical description of the dissociation problem for electron-hole pair on a one-dimensional chain in the hopping regime is proposed. Widely used results of Frenkel and Onsager theories are obtained as particular cases of the general solution. The application of the analytical theory ... [Phys. Rev. Lett. 100, 196602 (2008)] published Thu May 15, 2008.

Filling Factor Dependence of the Fractional Quantum Hall Effect Gap

V. S. Khrapai, A. A. Shashkin, M. G. Trokina, V. T. Dolgopolov, V. Pellegrini et al.
We directly measure the chemical potential jump in the low-temperature limit when the filling factor traverses the nu=1/3 and nu=2/5 fractional gaps in two-dimensional (2D) electron system in GaAs/AlGaAs single heterojunctions. In high magnetic fields B, both gaps are linear functions of B with slop ... [Phys. Rev. Lett. 100, 196805 (2008)] published Thu May 15, 2008.

Full Counting Statistics as the Geometry of Two Planes

Y. B. Sherkunov, A. Pratap, B. Muzykantskii, and N. d'Ambrumenil
Provided the measuring time is short enough, the full counting statistics (FCS) of the charge pumped across a barrier as a result of a series of voltage pulses are shown to be equivalent to the geometry of two planes. This formulation leads to the FCS without the need for the usual nonequilibrium (K ... [Phys. Rev. Lett. 100, 196601 (2008)] published Thu May 15, 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.

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.

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.

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.

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.

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.

Energy bandgap bowing of InAlN alloys studied by spectroscopic ellipsometry

E. Iliopoulos, A. Adikimenakis, C. Giesen, M. Heuken, and A. Georgakilas
InAlN films were heteroepitaxially grown on AlN/AlO (0001) templates by molecular beam epitaxy. The compositions studied spanned the whole ternary range. The complex dielectric function of the films was investigated by variable angle spectroscopic ellipsometry in the energy range from 0.55 to 6 e ... [Appl. Phys. Lett. 92, 191907 (2008)] published Wed May 14, 2008.

Enhancement of charge and energy storage in sol-gel derived pure and La-modified PbZrO[sub 3] thin films

Jayanta Parui and S. B. Krupanidhi
Antiferroelectric lanthanum-modified PbZrO thin films with La contents between 0 and 6 at. % have been deposited on Pt(111)/Ti/SiO/Si substrate by sol-gel route. On the extent of La-modification, maximum polarization (P) and recoverable energy density (W) have been enhanced followed by their subse ... [Appl. Phys. Lett. 92, 192901 (2008)] published Wed May 14, 2008.

Conductive atomic force microscopy of InAs/GaAs quantum rings

Tomaz Mlakar, Giorgio Biasiol, Stefan Heun, Lucia Sorba, T. Vijaykumar et al.
The properties of self-assembled InAs/GaAs quantum rings are investigated by conductive atomic force microscopy. Our two-dimensional current maps and current-voltage curves show a lower conductivity of the central ring hole as compared to rim and surrounding planar region. This result is quite surpr ... [Appl. Phys. Lett. 92, 192105 (2008)] published Wed May 14, 2008.

Quantum interference effects and magnetic scattering in the electrical resistivity of Ni nanocrystallites in TiN matrix

P. Khatua, T. K. Nath, Mitali Banerjee, and A. K. Majumdar
The electrical resistivity, rho of self-assembled, epitaxial nickel nanocrystallites in titanium nitride (TiN) matrix, was measured in fields from 0 to 4 T between 4.2 and 300 K. At lower temperatures, rho(T) conclusively shows sqrt(T) dependence below the observed minima at T unlike ln T in tw ... [Appl. Phys. Lett. 92, 193106 (2008)] published Wed May 14, 2008.

Erratum: ``A surface-enhanced Raman spectroscopy substrate for highly sensitive label-free immunoassay'' [Appl. Phys. Lett. 92, 043116 (2008)]

Ming-Liang Zhang, Chang-Qing Yi, Xia Fan, Kui-Qing Peng, Ming-Wang Shao et al.
... [Appl. Phys. Lett. 92, 199901 (2008)] published Wed May 14, 2008.

Experimental study of space-charge-limited flows in a nanogap

Sudeep Bhattacharjee, Adish Vartak, and Victor Mukherjee
An experimental investigation of space-charge-limited flow of current in a nanogap is presented. Electrodes with gap size d~70110 nm corresponding to d/lambda~(15) x 10, where lambda is the de Broglie wavelength of the space-charge electrons are experimented. Unlike classical ChildLangmuir's (CL) l ... [Appl. Phys. Lett. 92, 191503 (2008)] published Wed May 14, 2008.

Valence band offset of ZnO/4H-SiC heterojunction measured by x-ray photoelectron spectroscopy

H. B. Fan, G. S. Sun, S. Y. Yang, P. F. Zhang, R. Q. Zhang et al.
The valence band offset (VBO) of the wurtzite ZnO/4H-SiC heterojunction is directly determined to be 1.610.23 eV by x-ray photoelectron spectroscopy. The conduction band offset is deduced to be 1.500.23 eV from the known VBO value, which indicates a type-II band alignment for this heterojunction. ... [Appl. Phys. Lett. 92, 192107 (2008)] published Wed May 14, 2008.

Construction of a generalized gradient approximation by restoring the density-gradient expansion and enforcing a tight Lieb--Oxford bound

Yan Zhao and Donald G. Truhlar
Recently, a generalized gradient approximation (GGA) to the density functional, called PBEsol, was optimized (one parameter) against the jellium-surface exchange-correlation energies, and this, in conjunction with changing another parameter to restore the first-principles gradient expansion for exch ... [J. Chem. Phys. 128, 184109 (2008)] published Wed May 14, 2008.

Confinement effects on decay rate of surface electron states over liquid helium

S. S. Sokolov, Yu. P. Monarkha, J. M. Villas-Boas, and Nelson Studart
The decay rate of excited states of surface electrons in liquid helium, trapped in a quantum dot system, is evaluated, taking into account the process of spontaneous radiation of two ripplons with short wavelength. It is found that the values of the decay rate in later process are rather higher than ... [Low Temp. Phys. 34, 385 (2008)] published Wed May 14, 2008.

Chudnovsky Replies:

Eugene M. Chudnovsky
A Reply to the Comment by V. Ya. Kravchenko. ... [Phys. Rev. Lett. 100, 199704 (2008)] published Wed May 14, 2008.

Linear Plasmon Dispersion in Single-Wall Carbon Nanotubes and the Collective Excitation Spectrum of Graphene

C. Kramberger, R. Hambach, C. Giorgetti, M. H. Rummeli, M. Knupfer et al.
We have measured a strictly linear pi plasmon dispersion along the axis of individualized single-wall carbon nanotubes, which is completely different from plasmon dispersions of graphite or bundled single-wall carbon nanotubes. Comparative ab initio studies on graphene-based systems allow us to repr ... [Phys. Rev. Lett. 100, 196803 (2008)] published Wed May 14, 2008.

Comment on ``Theory of Spin Hall Effect: Extension of the Drude Model''

V. Ya. Kravchenko
A Comment on the Letter by Eugene M. Chudnovsky, [Phys. Rev. Lett. 99, 206601 (2007)]. The authors of the Letter offer a Reply. ... [Phys. Rev. Lett. 100, 199703 (2008)] published Wed May 14, 2008.

Electron-Vibration Interaction in Single-Molecule Junctions: From Contact to Tunneling Regimes

O. Tal, M. Krieger, B. Leerink, and J. M. van Ruitenbeek
Point contact spectroscopy on a HO molecule bridging Pt electrodes reveals a clear crossover between enhancement and reduction of the conductance due to electron-vibration interaction. As single-channel models predict such a crossover at a transmission probability of tau=0.5, we used shot noise meas ... [Phys. Rev. Lett. 100, 196804 (2008)] published Wed May 14, 2008.

Radiative recombination dynamics in tetrapod-shaped CdTe nanocrystals: Evidence for a photoinduced screening of the internal electric field

Giovanni Morello, Davide Tari, Luigi Carbone, Liberato Manna, Roberto Cingolani et al.
We study the radiative recombination processes in CdTe tetrapod nanocrystals at 10 K. Two intrinsic emission bands, namely the ground state (GS) and the excited state (EX), decay with three time constants, due to a power dependent Auger-like recombination process (tens of picoseconds), to the intri ... [Appl. Phys. Lett. 92, 191905 (2008)] published Tue May 13, 2008.

Intersubband transitions in ZnO multiple quantum wells

M. Belmoubarik, K. Ohtani, and H. Ohno
Intersubband transitions in ZnO/MgZnO multiple quantum wells (MQWs) are investigated by a photocurrent spectroscopy. Photocurrent peaks are observed in the energy range from 300 to 400 meV and shifted to higher energy by reducing the ZnO well thickness. Polarization-resolved photocurrent spectra ... [Appl. Phys. Lett. 92, 191906 (2008)] published Tue May 13, 2008.

Carrier relaxation dynamics in InAs/InP quantum dots

P. Miska, J. Even, O. Dehaese, and X. Marie
The electronic properties of InAs/InP(113)B double-cap quantum dots (QDs) emitting around 1.55 [mu]m are investigated. The carrier dynamics in QDs is studied by nonresonant time-resolved photoluminescence experiments. This analysis reveals the electronic structure of the QDs and the transient filli ... [Appl. Phys. Lett. 92, 191103 (2008)] published Tue May 13, 2008.

Hole recapture limited single photon generation from a single n-type charge-tunable quantum dot

P. A. Dalgarno, J. McFarlane, D. Brunner, R. W. Lambert, B. D. Gerardot et al.
The complete control of the electron occupation of a single InGaAs dot is shown to produce highly antibunched single photon emission with nonresonant optical excitation. Intensity correlation measurements show g(0) values of 3% (50%) at low (high) excitation power. A distinct double peak structure i ... [Appl. Phys. Lett. 92, 193103 (2008)] published Tue May 13, 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.

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.

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.

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.

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.

Mapping exciton quenching in photovoltaic-applicable polymer blends using time-resolved scanning near-field optical microscopy

A. Cadby, G. Khalil, A. M. Fox, and D. G. Lidzey
We have used time-resolved scanning near-field microscopy to image the fluorescence decay lifetime across a phase-separated blend of the photovoltaic-applicable polymers poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) and poly(9,9-dioctylfluorene-alt-bis- N,N-(4-butylphenyl)-bis-N,N-phenyl-1,4 ... [J. Appl. Phys. 103, 093715 (2008)] published Tue May 13, 2008.

Electrical properties of A/B-site substituted Ni-deficient La(Ni[sub 0.6]Fe[sub 0.3])O[sub 3] perovskites with A = Ag[sup +], Pb[sup 2+], Nd[sup 3+] and B = Mn[sup 3+], Ga[sup 3+]

Chang-Yi Chou, N. Kaurav, Yung-Kang Kuo, and Dong-Hau Kuo
We report the structural and electron transport properties of a series of compounds where A/B-site substituted Ni-deficient La(NiFe)O compounds with A=Ag, Pb, Nd and B=Mn, Ga have been synthesized by a chemical route. Electrical resistivity was used as an indicator to explore the response of La(NiFe ... [J. Appl. Phys. 103, 093716 (2008)] published Tue May 13, 2008.

Nanoporous alumina enhanced surface plasmon resonance sensors

Alexandros G. Koutsioubas, Nikolaos Spiliopoulos, Dimitris Anastassopoulos, Alexandros A. Vradis, and George D. Priftis
The signal enhancement of an easy to fabricate, nanoporous alumina assisted surface plasmon resonance (SPR) sensor is investigated. It is theoretically shown that the presence of a thin (under 200 nm) porous alumina layer on top of an aluminum film supporting the surface plasmons, may significantly ... [J. Appl. Phys. 103, 094521 (2008)] published Tue May 13, 2008.

Hartree--Fock calculations with linearly scaling memory usage

Elias Rudberg, Emanuel H. Rubensson, and Pawel Salek
We present an implementation of a set of algorithms for performing HartreeFock calculations with resource requirements in terms of both time and memory directly proportional to the system size. In particular, a way of directly computing the HartreeFock exchange matrix in sparse form is described whi ... [J. Chem. Phys. 128, 184106 (2008)] published Tue May 13, 2008.

Interface electronic states and molecular structure of a triarylamine based hole conductor on rutile TiO[sub 2](110)

E. M. J. Johansson, M. Odelius, P. G. Karlsson, H. Siegbahn, A. Sandell et al.
The molecular and electronic surface structure of a triarylamine based hole-conductor (HC) molecule evaporated onto rutile TiO(110) single crystal is investigated by means of synchrotron light based photoelectron spectroscopy and x-ray absorption spectroscopy in combination with calculations based o ... [J. Chem. Phys. 128, 184709 (2008)] published Tue May 13, 2008.

Erratum: Room Temperature Electrical Detection of Spin Coherence in C[sub 60] [Phys. Rev. Lett. [bold 98], 216601 (2007)]

W. Harneit, C. Boehme, S. Schaefer, K. Huebener, K. Fostiropoulos et al.
... [Phys. Rev. Lett. 100, 199904 (2008)] published Tue May 13, 2008.

Pseudogap and Charge Density Waves in Two Dimensions

S. V. Borisenko, A. A. Kordyuk, A. N. Yaresko, V. B. Zabolotnyy, D. S. Inosov et al.
Using angle-resolved photoemission spectroscopy we demonstrate that a normal-state pseudogap exists above T in one of the most studied two-dimensional charge-density wave (CDW) dichalcogenides 2H-TaSe. The initial formation of the incommensurate CDW is confirmed as being driven by a conventional nes ... [Phys. Rev. Lett. 100, 196402 (2008)] published Tue May 13, 2008.

Shot Noise in Ballistic Graphene

R. Danneau, F. Wu, M. F. Craciun, S. Russo, M. Y. Tomi et al.
We have investigated shot noise in graphene field effect devices in the temperature range of 4.230 K at low frequency (f=600850 MHz). We find that for our graphene samples with a large width over length ratio W/L, the Fano factor [fraktur F] reaches a maximum [fraktur F]~1/3 at the Dirac point and ... [Phys. Rev. Lett. 100, 196802 (2008)] published Tue May 13, 2008.

Nanoscale High Energetic Materials: A Polymeric Nitrogen Chain N[sub 8] Confined inside a Carbon Nanotube

Hakima Abou-Rachid, Anguang Hu, Vladimir Timoshevskii, Yanfeng Song, and Louis-Simon Lussier
We present a theoretical study of a new hybrid material, nanostructured polymeric nitrogen, where a polymeric nitrogen chain is encapsulated in a carbon nanotube. The electronic and structural properties of the new system are studied by means of ab initio electronic structure and molecular dynamics ... [Phys. Rev. Lett. 100, 196401 (2008)] published Tue May 13, 2008.

Interlevel transitions and two-photon processes in Ge/Si quantum dot photocurrent

E. Finkman, N. Shuall, A. Vardi, V. Le Thanh, and S. E. Schacham
Photocurrent spectra due to interlevel transitions of holes in Ge/Si quantum dots show several peaks in the range of 60300 meV, which superlinearly increase with bias, indicating release of carriers by tunneling. The relative peak intensity drastically changes with applied voltage, its polarity, and ... [J. Appl. Phys. 103, 093114 (2008)] published Mon May 12, 2008.

Electronic structure of a laterally graded ZrO[sub 2]--TiO[sub 2] film on Si(100) prepared by metal-organic chemical vapor deposition in ultrahigh vacuum

J. H. Richter, P. G. Karlsson, and A. Sandell
A TiOZrO film with laterally graded stoichiometry has been prepared by metal-organic chemical vapor deposition in ultrahigh vacuum. The film was characterized in situ using synchrotron radiation photoelectron spectroscopy (PES) and x-ray absorption spectroscopy. PES depth profiling clearly shows tha ... [J. Appl. Phys. 103, 094109 (2008)] published Mon May 12, 2008.

Origin of current oscillations in a polymeric electrochemically controlled element

Anteo Smerieri, Victor Erokhin, and Marco P. Fontana
We present a model for describing electrical properties of an electrochemically controlled heterojunction between a conducting polymer (polyaniline) and a solid electrolyte (lithium salt doped polyethylene oxide). In particular, the difference in the kinetics of the conductivity variation for differ ... [J. Appl. Phys. 103, 094517 (2008)] published Mon May 12, 2008.

Two-dimensional electron gas density in Al[sub 1 - x]In[sub x]N/AlN/GaN heterostructures (0.03 <= x <= 0.23)

M. Gonschorek, J.-F. Carlin, E. Feltin, M. A. Py, N. Grandjean et al.
Compared to the AlGaN alloy, which can only be grown under tensile strain on GaN, the AlInN alloy is predicted by Vegard's law to be lattice-matched (LM) on fully relaxed GaN templates for an indium content of ~17.5%, i.e., it can be grown either tensely or compressively on GaN. The effect of strain ... [J. Appl. Phys. 103, 093714 (2008)] published Mon May 12, 2008.

Enhanced Hall effect in Fe[sub x]Ge[sub 1 - x] nanocomposite films

W. B. Mi, Y. W. Liu, E. Y. Jiang, and H. L. Bai
Enhanced Hall effect has been observed in the FeGe nanocomposite films composed of nanoscale Fe grains embedded in amorphous Ge matrix. The Fe grain size, the saturation magnetization, and the interparticle interaction increase with increasing Fe atomic fraction x. The transport mechanism of the fil ... [J. Appl. Phys. 103, 093713 (2008)] published Mon May 12, 2008.

Intensity analysis and crystal-field modeling of Ho[sup 3+] in KPb[sub 2]Cl[sub 5] host

Dhiraj K. Sardar, Sree R. Chandrasekharan, Kelly L. Nash, John B. Gruber, Arnold Burger et al.
Optical absorption and emission intensities are investigated for Ho doped into single-crystal KPbCl. Room temperature absorption spectra of Ho(4f), representing transitions from I to excited multiplet manifolds observed between 400 and 2100 nm, have been analyzed using the JuddOfelt (JO) model to ob ... [J. Appl. Phys. 103, 093112 (2008)] published Mon May 12, 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.

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.

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.

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.

Interface formation and electronic structure of alpha-sexithiophene on ZnO

S. Blumstengel, N. Koch, S. Sadofev, P. Schafer, H. Glowatzki et al.
Interface formation between the organic semiconductor alpha-sexithiophene (6T) and polar as well as nonpolar ZnO surfaces is investigated. The growth mode of the organic layer is strongly influenced by the orientation of the ZnO surface. No indication for chemisorption of 6T on ZnO is found by photo ... [Appl. Phys. Lett. 92, 193303 (2008)] published Mon May 12, 2008.

Polyheteroarylene films with intrinsic switching mechanism for nonvolatile memory applications

A. Zherebov, A. Lachinov, J. Genoe, and A. Tameev
This paper presents a polymer material for the nonvolatile memory applications. Current-voltage characteristics show the reproducible nonvolatile switching effect. The effect is observed not only when using two metallic electrodes but also when using two semiconducting electrodes, which reveals the ... [Appl. Phys. Lett. 92, 193302 (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.

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.

Characterizing Nanometer Sized Platinum Films for Temperature Measurements

Fred Lacy
Sensors for temperature detection can be achieved with platinum films. After these metallic films have been fabricated, measurements of the electrical resistance will correspond to the temperature of the film. Although metals have a well characterized temperature-resistance relationship, this relati ... [AIP Conf. Proc. 1007, 128 (2008)] published Mon May 12, 2008.

Kiran et al. Reply:

B. Kiran, P. Jena, X. Li, A. Grubisic, S. T. Stokes et al.
A Reply to the Comment by Jaehoon Jung and Young-Kyu Han. ... [Phys. Rev. Lett. 100, 199702 (2008)] published Mon May 12, 2008.

Comment on ``Magic Rule for Al[sub n]H[sub m] Magic Clusters''

Jaehoon Jung and Young-Kyu Han
A Comment on the Letter by B. Kiran et al., Phys. Rev. Lett. 98, 256802 (2007). The authors of the Letter offer a Reply. ... [Phys. Rev. Lett. 100, 199701 (2008)] published Mon May 12, 2008.

Interchain coupling effects on dynamics of photoexcitations in conjugated polymers

Y. Meng, B. Di, X. J. Liu, Z. An, and C. Q. Wu
Within an extended SuSchriefferHeeger model including interchain interactions and the extended Hubbard model, the dynamical relaxation of photoexcitations in two coupled conjugated polymer chains is investigated by using a nonadiabatic evolution method. Initially, one of the two chains is photoexcit ... [J. Chem. Phys. 128, 184903 (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.

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.

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.

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.

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.

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.

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.

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.

Incorporation of Gold into Porous Anodic Alumina Formed on an Al--Au Alloy

S. J. Garcia-Vergara, M. Curioni, F. Roeth, T. Hashimoto, P. Skeldon et al.
An Al1 atom % Au gold alloy is employed to investigate the incorporation of a nonoxidized alloying element into porous anodic alumina films formed in phosphoric acid and sulfuric acid electrolytes. Gold is shown to enrich in the alloy in the initial stages of film growth, when a gold-free film is ... [J. Electrochem. Soc. 155, C333 (2008)] published Fri May 9, 2008.

Giant carrier mobility in single crystals of FeSb[sub 2]

Rongwei Hu, V. F. Mitrovic, and C. Petrovic
We report the giant carrier mobility in single crystals of FeSb. Nonlinear field dependence of Hall resistivity is well described with the two-carrier model. Maximum mobility values in high mobility band reach ~10 cm/V s at 8 K and are ~10 cm/V s at the room temperature. Our results point to a ... [Appl. Phys. Lett. 92, 182108 (2008)] published Fri May 9, 2008.

DX centers in CdTe: A density functional study

Mao-Hua Du
DX centers induced by both group-III and group-VII donors in CdTe are studied using density functional calculations. The results show that, for group-VII donors, the DX centers with a cation-cation bond (alpha- and beta-CCB-DX centers) are more stable than the previously proposed broken-bond DX (BB- ... [Appl. Phys. Lett. 92, 181908 (2008)] published Fri May 9, 2008.

Tuning the band structures of single walled silicon carbide nanotubes with uniaxial strain: A first principles study

Zhiguo Wang, Xiaotao Zu, Haiyan Xiao, Fei Gao, and William J. Weber
Electronic band structures of single-walled silicon carbide nanotubes are studied under uniaxial strain using first principles calculations. The band structure can be tuned by mechanical strain in a wide energy range. The band gap decreases with uniaxial tensile strain, but initially increases with ... [Appl. Phys. Lett. 92, 183116 (2008)] published Fri May 9, 2008.

Enhanced Seebeck coefficient in EuTe/PbTe [100] short-period superlattices

Akihiro Ishida, Daoshe Cao, Sinsuke Morioka, Martin Veis, Yoku Inoue et al.
Theoretical and experimental studies on Seebeck effect in EuTe/PbTe superlattices were performed. Theoretical calculations, which take into account temperature dependent band gap, nonparabolicity, and anisotropy of effective masses in the PbTe conduction band, were performed in the framework of Bolt ... [Appl. Phys. Lett. 92, 182105 (2008)] published Fri May 9, 2008.

Stress-induced morphology and fine-line stability enhancement of NiSi on poly-SiGe with a buffer polycrystalline silicon interlayer

Chi-Chang Wu, Wen-Fa Wu, Fu-Hsiang Ko, Hsin-Chiang You, and Wen-Luh Yang
The thermal and morphological stability of NiSi is enhanced by inserting a polycrystalline (poly-Si) buffer layer between the Ni and poly-SiGe films. NiSi films formed on poly-Si/poly-SiGe stack layers possessed continuous, smooth structures after annealing at 500850 degrees C. Moreover, nickel ge ... [Appl. Phys. Lett. 92, 182106 (2008)] published Fri May 9, 2008.

Electroresistance of La[sub 0.8]Li[sub 0.2]MnO[sub 3]

R. A. Lewis
The electroresistance of LaLiMnO has been measured at many applied currents and temperatures. As the magnitude of the current decreases, the electroresistance becomes more pronounced. Substantial electroresistance is observed over a wide range of temperatures. The greatest effect occurs well below t ... [Appl. Phys. Lett. 92, 184102 (2008)] published Fri May 9, 2008.