Devil's staircases and supersolids in a one-dimensional dipolar Bose gas
F. J. Burnell, Meera M. Parish, N. R. Cooper, and S. L. Sondhi
We consider a single-component gas of dipolar bosons confined in a one-dimensional optical lattice, where the dipoles are aligned such that the long-ranged dipolar interactions are maximally repulsive. In the limit of zero intersite hopping and sufficiently large on-site interaction, the phase diagr ... [Phys. Rev. B 80, 174519 (2009)] published Thu Nov 19, 2009.
Bose-Einstein Condensation in Quantum Glasses
Giuseppe Carleo, Marco Tarzia, and Francesco Zamponi
The role of geometrical frustration in strongly interacting bosonic systems is studied with a combined numerical and analytical approach. We demonstrate the existence of a novel quantum phase featuring both Bose-Einstein condensation and spin-glass behavior. The differences between such a phase and ... [Phys. Rev. Lett. 103, 215302 (2009)] published Wed Nov 18, 2009.
Zero-point divacancy concentration in the shadow wave function model for solid He
R. Pessoa, M. de Koning, and S. A. Vitiello
We address the issue of interaction between zero-point vacancies in solid He as described within the shadow wave function model. Applying the reversible-work method and taking into account finite-size effects, we obtain a zero-point monovacancy concentration of (2.030.02) x 10, which is slightly hig ... [Phys. Rev. B 80, 172302 (2009)] published Mon Nov 16, 2009.
Multiparticle Composites in Density-Imbalanced Quantum Fluids
Evgeni Burovski, Giuliano Orso, and Thierry Jolicoeur
We consider two-component one-dimensional quantum gases with a density imbalance. While generically such fluids are two-component Luttinger liquids, we show that if the ratio of the densities is a rational number, p/q, and mass asymmetry between components is sufficiently strong, one of the two eige ... [Phys. Rev. Lett. 103, 215301 (2009)] published Mon Nov 16, 2009.
Ferronematic Ground State of the Dilute Dipolar Fermi Gas
Benjamin M. Fregoso and Eduardo Fradkin
It is shown that a homogeneous two-component Fermi gas with (long-range) dipolar and short-range isotropic interactions has a ferronematic phase for suitable values of the dipolar and short-range coupling constants. The ferronematic phase is characterized by having a nonzero magnetization and long-r ... [Phys. Rev. Lett. 103, 205301 (2009)] published Fri Nov 13, 2009.
Quantum phase diagrams of fermionic dipolar gases in a planar array of one-dimensional tubes
Yi-Ping Huang and Daw-Wei Wang
We systematically study ground-state properties of fermionic dipolar gases in a planar array of one-dimensional potential tubes for arbitrary orientation of dipole moments. Using the Luttinger liquid theory with the generalized Bogoliubov transformation, we calculate the elementary excitations and t ... [Phys. Rev. A 80, 053610 (2009)] published Thu Nov 12, 2009.
Symmetry breaking of the density distribution of a quantum fluid in a nanoslit
Gersh O. Berim and Eli Ruckenstein
The phenomenon of symmetry breaking (SB) of the fluid density distribution in a slit between parallel identical solid walls examined previously for a classical fluid (argon) [G. O. Berim and E. Ruckenstein, J. Chem. Phys. 126, 124503 (2007)] is examined for a quantum fluid (He) on the basis of a non ... [J. Chem. Phys. 131, 184707 (2009)] published Wed Nov 11, 2009.
Mott transitions in ternary flavor mixtures of ultracold fermions on optical lattices
E. V. Gorelik and N. Blumer
Ternary flavor mixtures of ultracold fermionic atoms in an optical lattice are studied in the case of equal repulsive on-site interactions U>0. The corresponding SU(3) invariant Hubbard model is solved numerically exactly within dynamical mean-field theory using multigrid Hirsch-Fye quantum Monte Ca ... [Phys. Rev. A 80, 051602 (2009)] published Wed Nov 11, 2009.
Multiresonant Spinor Dynamics in a Bose-Einstein Condensate
C. Klempt, O. Topic, G. Gebreyesus, M. Scherer, T. Henninger et al.
We analyze the spinor dynamics of a Rb F=2 condensate initially prepared in the m=0 Zeeman sublevel. We show that this dynamics, characterized by the creation of correlated atomic pairs in m=1, presents an intriguing multiresonant magnetic-field dependence induced by the trap inhomogeneity. This dep ... [Phys. Rev. Lett. 103, 195302 (2009)] published Fri Nov 6, 2009.
Negative impurity ions in liquid He
F. Ancilotto, M. Barranco, and M. Pi
We present theoretical results, based on zero-temperature density-functional theory, for the formation and properties of a negative impurity ion in bulk liquid He. We first consider Ca which, due to its very low electron affinity, does not easily form a negative ion in vacuum. We show that a neutral ... [Phys. Rev. B 80, 174504 (2009)] published Wed Nov 4, 2009.
Off-diagonal long-range order and supersolidity in a quantum solid with vacancies
Yu Shi, Yin Yang, and Shao-Ming Fei
We consider a lattice of bosonic atoms, whose number N may be smaller than the number of lattice sites M. We study the Hartree-Fock wave function built up from localized wave functions w(r) of single atoms, with nearest-neighboring overlap. The zero-momentum particle number is expressed in terms of ... [Phys. Rev. B 80, 174503 (2009)] published Tue Nov 3, 2009.
Lifshitz Point in the Phase Diagram of Resonantly Interacting Li-K Mixtures
K. B. Gubbels, J. E. Baarsma, and H. T. C. Stoof
We consider a strongly interacting Li-K mixture, which is imbalanced both in the masses and the densities of the two fermionic species. At present, it is the experimentalist's favorite for reaching the superfluid regime. We construct an effective thermodynamic potential that leads to excellent agree ... [Phys. Rev. Lett. 103, 195301 (2009)] published Tue Nov 3, 2009.
Dynamic many-body theory: Pair fluctuations in bulk He
C. E. Campbell and E. Krotscheck
Dynamical excitations in bulk liquid He are investigated by using a manifestly microscopic theory of excitations that includes multiple-phonon scattering. The wave function of the dynamic system is represented in terms of one- and two-body excitation amplitudes. Equations of motion for the linear re ... [Phys. Rev. B 80, 174501 (2009)] published Mon Nov 2, 2009.
Erratum: Discerning Incompressible and Compressible Phases of Cold Atoms in Optical Lattices [Phys. Rev. Lett. 102, 135302 (2009)]
V. W. Scarola, L. Pollet, J. Oitmaa, and M. Troyer
Abstract not available. [Phys. Rev. Lett. 103, 189901 (2009)] published Thu Oct 29, 2009.
Fermionic Collective Excitations in a Lattice Gas of Rydberg Atoms
B. Olmos, R. Gonzalez-Ferez, and I. Lesanovsky
We investigate the many-body quantum states of a laser-driven gas of Rydberg atoms confined to a large spacing ring lattice. If the laser driving is much stronger than the van der Waals interaction among the Rydberg atoms, these many-body states are collective fermionic excitations. The first excite ... [Phys. Rev. Lett. 103, 185302 (2009)] published Wed Oct 28, 2009.
Magnetoroton Softening in Rb Spinor Condensates with Dipolar Interactions
R. W. Cherng and E. Demler
Superfluids with a tendency towards periodic order have both phonon- and rotonlike spectra. We show that magnetoroton softening occurs in Rb spinor condensates. A rich variety of dynamical instabilities emerges as a function of the magnetic field orientation and strength of the quadratic Zeeman shif ... [Phys. Rev. Lett. 103, 185301 (2009)] published Tue Oct 27, 2009.
Underlying Mechanism for the Giant Isochoric Compressibility of Solid he: Superclimb of Dislocations
S. G. Soyler, A. B. Kuklov, L. Pollet, N. V. Prokof'ev, and B. V. Svistunov
In the experiment on superfluid transport in solid He [Phys. Rev. Lett. 100, 235301 (2008)], Ray and Hallock observed an anomalously large isochoric compressibility: the supersolid samples demonstrated a significant and apparently spatially uniform response of density and pressure to chemical potent ... [Phys. Rev. Lett. 103, 175301 (2009)] published Thu Oct 22, 2009.
Nonuniversal behavior of cold Fermi condensates with narrow Feshbach resonances
Chi-Yong Lin, Da-Shin Lee, and Ray J. Rivers
In this paper, we construct an effective field theory for a condensate of cold Fermi atoms whose scattering is controlled by a narrow Feshbach resonance. We show how, from first principles, it permits a hydrodynamic description of the BEC-BCS crossover from which the equation of state, intimately re ... [Phys. Rev. A 80, 043621 (2009)] published Wed Oct 21, 2009.
Exact ground state Monte Carlo method for Bosons without importance sampling
M. Rossi, M. Nava, L. Reatto, and D. E. Galli
Generally exact quantum Monte Carlo computations for the ground state of many bosons make use of importance sampling. The importance sampling is based either on a guiding function or on an initial variational wave function. Here we investigate the need of importance sampling in the case of path inte ... [J. Chem. Phys. 131, 154108 (2009)] published Mon Oct 19, 2009.
Quadrupole oscillations in Bose-Fermi mixtures of ultracold atomic gases made of Yb atoms in the time-dependent Gross-Pitaevskii and Vlasov equations
Tomoyuki Maruyama and Hiroyuki Yabu
We study quadrupole collective oscillations in the bose-fermi mixtures of ultracold atomic gases of Yb isotopes, which are realized by Kyoto group. Three kinds of combinations are chosen, Yb-Yb, Yb-Yb and Yb-Yb, where boson-fermion interactions are weakly repulsive, strongly attractive and strongly ... [Phys. Rev. A 80, 043615 (2009)] published Mon Oct 19, 2009.
Spin Drag in Noncondensed Bose Gases
R. A. Duine and H. T. C. Stoof
We show how time-dependent magnetic fields lead to spin motive forces and spin drag in a spinor Bose gas. We propose to observe these effects in a toroidal trap and analyze this particular proposal in some detail. In the linear-response regime we define a transport coefficient that is analogous to t ... [Phys. Rev. Lett. 103, 170401 (2009)] published Mon Oct 19, 2009.