Related papers: Phases and collective modes of bosons in a triangu…
We investigate the collective excitations of a low temperature dilute gas mixture that consists of a Bose-Einstein condensate and a Fermi-gas that is a normal (i.e. non-superfluid) Fermi-liquid. We find that the BEC-mediated fermion-fermion…
We establish the nature of the supersolid phase observed for hardcore bosons on the triangular lattice near half-integer filling factor, and study the phase diagram of the system at finite temperature. We find that the solid order is always…
Finite temperature simulations are used to study quadrupole excitations of a trapped Bose-Einstein condensate. We focus specifically on the m=0 mode, where a long-standing theoretical problem has been to account for an anomalous variation…
We examine the zero and finite temperature phase diagrams of soft-core bosons of the extended Bose-Hubbard model on a square optical lattice. To study various quantum phases and their transitions we employ single-site and cluster Gutzwiller…
We examine the low-lying collective quasiparticle modes of a quasi-one-dimensional mixture of Bose-Einstein condensates having dipolar and non-dipolar atomic species. The dipolar atomic species have permanent magnetic dipolar moments. We…
We investigate the quantum phases of monodispersed bosonic gases confined to a triangular lattice and interacting via a class of soft-shoulder potentials. The latter correspond to soft-core potentials with an additional hard-core onsite…
In this paper we present a very general theoretical framework for addressing fermionic superfluids over the entire range of BCS to Bose Einstein condensation (BEC) crossover in the presence of population imbalance or spin polarization. Our…
We study the physics of cold polar molecules loaded into an optical lattice in the regime of strong three-body interactions, as put forward recently by B\"uchler [Nature Phys. 3, 726 (2007)]. To this end quantum Monte Carlo simulations,…
We present a theoretical study of condensation of bosons in tight binding bands corresponding to simple cubic, body centered cubic, and face centered cubic lattices. We have analyzed non-interacting bosons, weakly interacting bosons using…
We study collective modes of vortex lattices in two-component Bose-Einstein condensates subject to synthetic magnetic fields in mutually parallel or antiparallel directions. By means of the Bogoliubov theory with the lowest-Landau-level…
We analyze the hard-core Bose-Hubbard model with both the three-body and nearest neighbor repulsions on the triangular lattice. The phase diagram is achieved by means of the semi-classical approximation and the quantum Monte Carlo…
We use high order linked cluster series to investigate the hard core boson model on the triangular lattice, at zero temperature. Our expansions, in powers of the hopping parameter $t$, probe the spatially ordered `solid' phase and the…
The properties of a macroscopic assembly of weakly-repulsive bosons at zero temperature are well described by Gross-Pitaevskii mean-field theory. According to this formalism the system exhibits a quantum transition from superfluid to…
By using slave particle (slave boson and slave fermion) technique on the Bose-Hubbard model, we study the finite temperature properties of ultracold Bose gases in optical lattices. The phase diagrams at finite temperature are depicted by…
We study a system of heteronuclear molecules on a triangular lattice and analyze the potential of this system for the experimental realization of a supersolid phase. The ground state phase diagram contains superfluid, solid and supersolid…
We derive a mean-field description for two-dimensional (2D) interacting Bose gases at arbitrary temperatures. We find that genuine Bose-Einstein condensation with long-range coherence only survives at zero temperature. At finite…
Dipolar Bose-Einstein condensates represent a powerful platform for the exploration of quantum many-body phenomena arising from long-range interactions. A series of recent experiments has demonstrated the formation of supersolid states of…
We investigate a supersolid state in hardcore boson models on the face-centered-cubic (FCC) lattice. The supersolid state is characterized by a coexistence of crystalline order and superfluidity. Using a quantum Monte Carlo method based on…
We consider a mixture of two-component Fermi and (one-component) bose gases under the repulsive Bose-Fermi and attractive Fermi-Fermi interaction. We perform a systematic study of the finite-temperature phase diagrams in the chemical…
Recent experiments with ultracold Rydberg-excited atoms have shown that long-range interactions can give rise to spatially ordered structures. Observation of crystalline phases in a system with Rydberg atoms loaded into an optical lattice…