Related papers: Quantum Fluctuations, Temperature and Detuning Eff…
We study radiation-matter interaction in a system of ultracold atoms trapped in an optical lattice in a Mott insulator phase. We develop a fully general quantum model, and we perform calculations for a one-dimensional geometry at normal…
We discuss a quantum transition from a superfluid to a Mott glass phases in disordered Bose-systems by the example of an isotropic spin-$\frac12$ antiferromagnet with spatial dimension $d\ge2$ and with disorder in tunable exchange…
We study ground-state phase diagrams and excitation spectra of Bose-Bose mixtures in an optical lattice by applying the Gutzwiller approximation to the two-component Bose-Hubbard model. A case of equal hoppings and equal intra-component…
A model of two-species bosons moving on the sites of a lattice is studied at nonzero temperature, focusing on magnetic order and superfluid-insulator transitions. Firstly, Landau theory is used to find the general structure of the phase…
We introduce a new renormalization group theory to examine the quantum phase transitions upon exiting the insulating phase of a disordered, strongly interacting boson system. For weak disorder we find a direct transition from this Mott…
We investigate the superfluid-Mott-insulator transition of a two-dimensional photon gas in a dye-filled optical microcavity and in the presence of a periodic potential. We show that in the random-phase approximation the effects of the dye…
We analyze the outcome of a Mott insulator to superfluid transition for a two-component Bose gas with two atoms per site in an optical lattice in the limit of slow ramping down the lattice potential. This manipulation of the initial Mott…
We study the superfluid to Mott-insulator (SF-MI) transition of hardcore bosons in commensurate superlattices in two and three dimensions. We focus on the special case where the superlattice has period two and the system is at half filling.…
By means of analytical and numerical methods we analyze the phase diagram of polaritons in one-dimensional coupled cavities. We locate the phase boundary, discuss the behavior of the polariton compressibility and visibility fringes across…
Quantum mixtures of moir\'e excitons have arisen as a platform for realizing novel phases of light and matter. Here, we study moir\'e polaritons coupled to a Bose-Einstein condensate of dark-state excitons confined to a moir\'e…
Quantum fluctuations in low-dimensional systems and near quantum phase transitions have significant influences on material properties. Yet, it is difficult to experimentally gauge the strength and importance of quantum fluctuations. Here we…
Quantum phases of matter are routinely identified by coherence features, with interference patterns being one of the most directly observable quantities. In lattices, the superfluid-to-Mott-insulator (SF-MI) transition is commonly viewed as…
Successive quantum transitions in an intermediate regime are shown to exist between the superfluid and Mott insulating states for interacting bosonic atoms in one dimension with a trapping potential. These transitions, which are caused by…
When atoms are loaded into an optical lattice, the process of gradually turning on the lattice is almost adiabatic. In this paper we investigate how the temperature changes when going from the gapless superfluid phase to the gapped Mott…
We study the zero-temperature phase transitions of two-dimensional superconducting arrays with both the self- and the junction capacitances in the presence of external magnetic fields. We consider two kinds of excitations from the Mott…
The Mott insulator-to-superfluid transition exhibited by the Bose-Hubbard model on a two-dimensional square lattice occurs for any value of the chemical potential, but becomes critical at the tips of the so-called Mott lobes only. Employing…
We consider variants of the Jaynes-Cummings-Hubbard model of lattice polaritons, taking into account next-nearest-neighbor, diagonal and long-range photon hopping in one and two dimensions. These models are relevant for potential…
We use quantum Monte Carlo simulations to study the phase diagram of hard-core bosons with short-ranged {\it attractive} interactions, in the presence of uniform diagonal disorder. It is shown that moderate disorder stabilizes a glassy…
Mean-field dynamics of strongly interacting bosons described by hard core bosons with nearest-neighbor attraction has been shown to support two species of solitons: one of Gross-Pitaevskii (GP-type) where the condensate fraction remains…
The two-orbital degenerate Hubbard model with distinct hopping integrals is studied by combining dynamical mean-field theory with quantum Monte Carlo simulations. The role of orbital fluctuations for the nature of the Mott transition is…