Superconductor-to-normal transitions in dissipative chains of mesoscopic grains and nanowires
The interplay of quantum fluctuations and dissipation in chains of mesoscopic
superconducting grains is analyzed and the results are applied to nanowires. It is shown that …
superconducting grains is analyzed and the results are applied to nanowires. It is shown that …
Quantum rotor description of the Mott-insulator transition in the Bose-Hubbard model
We present an approach to the Bose-Hubbard model using the U (1) quantum rotor
description. The effective action formalism allows us to formulate a problem in the phase …
description. The effective action formalism allows us to formulate a problem in the phase …
Interaction-driven crossover from Mott insulator–superfluid criticality to Bose-Einstein condensation in a simple cubic lattice
TK Kopeć - Physical Review B, 2024 - APS
We investigate how strongly interacting bosons, described by the Bose-Hubbard
Hamiltonian, transition from the Mott insulator to the superfluid phase and, ultimately, to a …
Hamiltonian, transition from the Mott insulator to the superfluid phase and, ultimately, to a …
Atom-atom correlations in time-of-flight imaging of ultracold bosons in optical lattices
TA Zaleski, TK Kopeć - Physical Review A—Atomic, Molecular, and Optical …, 2011 - APS
We study the spatial correlations of strongly interacting bosons in a ground state, confined in
a two-dimensional square and a three-dimensional cubic lattice. Using the combined …
a two-dimensional square and a three-dimensional cubic lattice. Using the combined …
Coulomb repulsion, phase stiffnesses, and doping-induced superconductivity from the Mott insulator in the model of high- cuprates
TK Kopeć - Physical Review B—Condensed Matter and Materials …, 2004 - APS
The electronic tt′-UJ model for the Cu O 2 plane in high-T c superconducting cuprates is
elaborated. It incorporates both charge transfer U and exchange correlation J with direct t …
elaborated. It incorporates both charge transfer U and exchange correlation J with direct t …
Finite-temperature effects on the superfluid Bose–Einstein condensation of confined ultracold atoms in three-dimensional optical lattices
We discuss the finite-temperature phase diagram in the three-dimensional Bose–Hubbard
(BH) model in the strong correlation regime, relevant for Bose–Einstein condensates in …
(BH) model in the strong correlation regime, relevant for Bose–Einstein condensates in …
Frustration effects in rapidly rotating square and triangular optical lattices
We discuss the ground state of the two-dimensional Bose-Hubbard (BH) Hamiltonian,
relevant for rotating gaseous Bose-Einstein condensates, by employing U (1) quantum rotor …
relevant for rotating gaseous Bose-Einstein condensates, by employing U (1) quantum rotor …
Three-dimensional Josephson-junction arrays in the quantum regime
We study the quantum phase transition properties of a three-dimensional periodic array of
Josephson junctions with charging energy that includes both the self and mutual junction …
Josephson junctions with charging energy that includes both the self and mutual junction …
Superconducting phase coherence and pairing gap in the three-dimensional attractive Hubbard model
TK Kopeć - Physical Review B, 2002 - APS
We consider a lattice version of the “negative-U” Hubbard model in three dimensions, to
study the crossover from a superconducting phase transition (dominated by phase …
study the crossover from a superconducting phase transition (dominated by phase …
Effect of next-nearest-neighbour hopping on Bose–Einstein condensation in optical lattices
TA Zaleski, TK Kopeć - Journal of Physics B: Atomic, Molecular …, 2010 - iopscience.iop.org
We study the influence of the various hopping elements on the ground state properties of the
bosons in the 2D optical square lattice. Using the quantum rotor approach for the Bose …
bosons in the 2D optical square lattice. Using the quantum rotor approach for the Bose …