Frictionless Flow in a Binary Polariton Superfluid
E. Cancellieri, F. M. Marchetti, M. H. Szymanska, D. Sanvitto, and C. Tejedor
We study the properties of a binary microcavity polariton superfluid coherently injected by two lasers at different momenta and energies. The crossover from the supersonic to the subsonic regime, where motion is frictionless, is described by evaluating the linear response of the system to a weak def ... [Phys. Rev. Lett. 108, 065301 ] published .
Binding and structure of tetramers in the scaling limit
M. R. Hadizadeh, M. T. Yamashita, Lauro Tomio, A. Delfino, and T. Frederico
The momentum-space structure of the Faddeev-Yakubovsky (FY) components of weakly bound tetramers is investigated at the unitary limit using a renormalized zero-range two-body interaction. The results, obtained by considering a given trimer level with binding energy B, provide further support to a un ... [Phys. Rev. A 85, 023610 ] published .
Few-body bound-state stability of dipolar molecules in two dimensions
A. G. Volosniev, D. V. Fedorov, A. S. Jensen, and N. T. Zinner
Bound structures among dipolar molecules in multilayers are a topic of great interest in the light of recent experiments that have demonstrated the feasibility of the setup. While it is known that two molecules in two adjacent layers will always bind, larger complexes have only been scarcely address ... [Phys. Rev. A 85, 023609 ] published .
Shear modulus of an elastic solid under external pressure as a function of temperature: The case of helium
Felipe Barra, Fernando Lund, Nicolas Mujica, and Sergio Rica
The energy of a dislocation loop in a continuum elastic solid under pressure is considered within the framework of classical mechanics. For a circular loop, this is a function with a maximum at pressures that are well within reach of experimental conditions for solid helium, suggesting, in this case ... [Phys. Rev. B 85, 064103 ] published .
Fermi polarons in two dimensions
Richard Schmidt, Tilman Enss, Ville Pietila, and Eugene Demler
We theoretically analyze inverse radio-frequency (rf) spectroscopy experiments in two-component Fermi gases. We consider a small number of impurity atoms interacting strongly with a bath of majority atoms. In two-dimensional geometries we find that the main features of the rf spectrum correspond to ... [Phys. Rev. A 85, 021602 ] published .
Size-induced melting and reentrant freezing in fullerene-doped helium clusters
F. Calvo
The structural and dynamical stabilities of CHe clusters are theoretically investigated using global optimization and path-integral simulation methods. Up to N=32, the fullerene ion traps the helium atoms onto sixfold and fivefold faces, strongly enough to negate vibrational delocalization. Above th ... [Phys. Rev. B 85, 060502 ] published .
Phase diagram of Landau-Zener phenomena in coupled one-dimensional Bose quantum fluids
Santiago F. Caballero-Benitez and Rosario Paredes
We study stationary and dynamical properties of the many-body Landau-Zener dynamics of a Bose quantum fluid confined in two coupled one-dimensional chains by using a many-body generalization recently reported Chen et al. [Nature Phys. 7, 61 (2011)], within the decoupling approximation and the one-le ... [Phys. Rev. A 85, 023605 ] published .
Quasiclassical and ultraquantum decay of superfluid turbulence
A. W. Baggaley, C. F. Barenghi, and Y. A. Sergeev
We address a question which, after a decade-long discussion, still remains open: what is the nature of the ultraquantum regime of decay of quantum turbulence? The model developed in this work reproduces both the ultraquantum and the quasiclassical decay regimes and explains their hydrodynamical natu ... [Phys. Rev. B 85, 060501 ] published .
Supercircle description of universal three-body states in two dimensions
F. F. Bellotti, T. Frederico, M. T. Yamashita, D. V. Fedorov, A. S. Jensen et al.
Bound states of asymmetric three-body systems confined to two dimensions are currently unknown. In the universal regime, two energy ratios and two mass ratios provide complete knowledge of the three-body energy measured in units of one two-body energy. We compute the three-body energy for general sy ... [Phys. Rev. A 85, 025601 ] published .
Rubidium-87 Bose-Einstein condensate in an optically plugged quadrupole trap
R. Dubessy, K. Merloti, L. Longchambon, P.-E. Pottie, T. Liennard et al.
We describe an experiment to produce Rb Bose-Einstein condensates in an optically plugged magnetic quadrupole trap, using a blue-detuned laser. Due to the large detuning of the plug laser with respect to the atomic transition, the evaporation has to be carefully optimized in order to efficiently ove ... [Phys. Rev. A 85, 013643 ] published .
Microscopic characterization of overpressurized superfluid He
M. Rossi, E. Vitali, L. Reatto, and D. E. Galli
We have studied static and dynamical properties of superfluid He at T=0 K in the pressure range from 6 up to 87 atm well above freezing into the metastable region. Zero temperature properties have been obtained with the exact shadow path integral ground state (SPIGS) method. Information about dynami ... [Phys. Rev. B 85, 014525 ] published .
Simulating Z topological insulators with cold atoms in a one-dimensional optical lattice
Feng Mei, Shi-Liang Zhu, Zhi-Ming Zhang, C. H. Oh, and N. Goldman
We propose an experimental scheme to simulate and detect the properties of time-reversal invariant topological insulators, using cold atoms trapped in one-dimensional bichromatic optical lattices. This system is described by a one-dimensional Aubry-Andre model with an additional SU(2) gauge structur ... [Phys. Rev. A 85, 013638 ] published .
Strong thermalization of the two-component Bose-Hubbard model at finite temperatures
J. M. Zhang, C. Shen, and W. M. Liu
We study thermalization of a two-component Bose-Hubbard model by exact diagonalization. Initially, the two components do not interact and are both at equilibrium but with different temperatures. As the onsite intercomponent interaction is turned on, perfect thermalization occurs. Remarkably, not mer ... [Phys. Rev. A 85, 013637 ] published .
Evolution from BCS to BEC superfluidity in the presence of spin-orbit coupling
Li Han and C. A. R. Sa de Melo
We discuss the evolution from BCS to Bose-Einstein condensate (BEC) superfluids in the presence of spin-orbit coupling for a balanced mixture of ultracold fermions. The dependence of several thermodynamic properties, such as chemical potential, order parameter, pressure, entropy, isothermal compress ... [Phys. Rev. A 85, 011606 ] published .
Onset Temperature of Bose-Einstein Condensation in Incommensurate Solid He
R. Rota and J. Boronat
The temperature dependence of the one-body density matrix in He crystals presenting vacancies is computed with path integral Monte Carlo simulations. The main purpose of this study is to estimate the onset temperature T of Bose-Einstein condensation in these systems. We see that T depends on the vac ... [Phys. Rev. Lett. 108, 045308 ] published .
Thermodynamics of a Bose-Einstein Condensate with Free Magnetization
B. Pasquiou, E. Marechal, L. Vernac, O. Gorceix, and B. Laburthe-Tolra
We study thermodynamic properties of a gas of spin 3Cr atoms across Bose-Einstein condensation. Magnetization is free, due to dipole-dipole interactions. We show that the critical temperature for condensation is lowered at extremely low magnetic fields, when the spin degree of freedom is thermally a ... [Phys. Rev. Lett. 108, 045307 ] published .
Correlated Phases of Bosons in the Flat Lowest Band of the Dice Lattice
G. Moller and N. R. Cooper
We study correlated phases occurring in the flat lowest band of the dice-lattice model at flux density one-half. We discuss how to realize this model, also referred to as the [script T] lattice, in cold atomic gases. We construct the projection of the model to the lowest dice band, which yields a Hu ... [Phys. Rev. Lett. 108, 045306 ] published .
Ultracold Atoms in a Tunable Optical Kagome Lattice
Gyu-Boong Jo, Jennie Guzman, Claire K. Thomas, Pavan Hosur, Ashvin Vishwanath et al.
We realize a two-dimensional kagome lattice for ultracold atoms by overlaying two commensurate triangular optical lattices generated by light at the wavelengths of 532 and 1064 nm. Stabilizing and tuning the relative position of the two lattices, we explore different lattice geometries including a k ... [Phys. Rev. Lett. 108, 045305 ] published .
Realization of a Resonant Fermi Gas with a Large Effective Range
E. L. Hazlett, Y. Zhang, R. W. Stites, and K. M. O'Hara
We have measured the interaction energy and three-body recombination rate for a two-component Fermi gas near a narrow Feshbach resonance and found both to be strongly energy dependent. Even for de Broglie wavelengths greatly exceeding the van der Waals length scale, the behavior of the interaction e ... [Phys. Rev. Lett. 108, 045304 ] published .
Universal Mechanism of Dissipation in Fermi Superfluids at Ultralow Temperatures
Mihail A. Silaev
We show that the vortex dynamics in Fermi superfluids at ultralow temperatures is governed by the local heating of the vortex cores creating the heat flux carried by nonequilibrium quasiparticles emitted by moving vortices. This mechanism provides a universal zero temperature limit of dissipation in ... [Phys. Rev. Lett. 108, 045303 ] published .
Collective modes of a strongly interacting Bose gas: Probing the Mott transition
Michiel Snoek
We analyze the collective modes of a harmonically trapped, strongly interacting Bose gas in an optical lattice in the vicinity of the Mott-insulator transition. For that aim we employ the dynamical Gutzwiller mean-field method, by performing real-time evolution and by solving the equations in linear ... [Phys. Rev. A 85, 013635 ] published .