54 citations · 197 across the 15 of their papers we have counts for
15 papers
Stability of the replica-symmetric solution in the off-diagonally-disordered Bose-Hubbard model
Anna M. Piekarska, Tadeusz K. Kopeć
We study a disordered system of interacting bosons described by the Bose-Hubbard Hamiltonian with random tunneling amplitudes. We derive the condition for the stability of the repl…
Emergence of a superglass phase in the random hopping Bose-Hubbard model
Anna M. Piekarska, Tadeusz K. Kopeć
We study an experimentally feasible system of strongly correlated bosons with random hoppings, described by the infinite-range Bose-Hubbard model on a lattice with hopping integral…
Ultraviolet absorption spectrum of the half-filled bilayer graphene
V. Apinyan, T. K. Kopec
We consider the optical properties of the half-filled AB-stacked bilayer graphene with the excitonic pairing and condensation between the layers. Both intra and interlayer local Co…
Spectral properties of excitons in the bilayer graphene
V. Apinyan, T. K. Kopeć
In this paper, we consider the spectral properties of the bilayer graphene with the local excitonic pairing interaction between the electrons and holes. We consider the generalized…
Two band model for coherent excitonic condensates
V. Apinyan, T. K. Kopeć
We consider the excitonic correlations in the two band solid state system composed of the valence band and conduction band electrons. We treat the phase coherence mechanism in the…
Excitonic gap formation and condensation in the bilayer graphene structure
V. Apinyan, T. K. Kopeć
We have studied the excitonic gap formation in the Bernal Stacked, bilayer graphene (BLG) structures at half-filling. Considering the local Coulomb interaction between the layers,…
Density of states and excitonic condensation in the double layer correlated systems
V. Apinyan, T. K. Kopeć
We consider the single-particle density of states (DOS) in the strongly correlated double layer (DL) system, without applied external fields. We demonstrate an unusual collapse eff…
Excitonic gap formation in neutral bilayer structures
V. Apinyan, T. K. Kopeć
We consider the pairing between conduction band electrons, and the valence band holes in the neutral bilayer-type structures. By employing the bilayer Hubbard model, we show the po…
The superfluid phase transition in two-dimensional excitonic systems
V. Apinyan, T. K. Kopeć
We study the superfluid phase transition in the two-dimensional (2D) excitonic system. Employing the extended Falicov-Kimball model (EFKM) and considering the local quantum correla…
Phase coherence and spectral functions in the two-dimensional excitonic systems
V. Apinyan, T. K. Kopeć
The nonlocal correlation mechanism between excitonic pairs is considered for a two dimensional exciton system. On the base of the unitary decomposition of the usual electron operat…
Atom-atom correlations in time-of-flight imaging of ultra-cold bosons in optical lattices
T. A. Zaleski, T. K. Kopeć
We study the spatial correlations of strongly interacting bosons in a ground state, confined in two-dimensional square and three-dimensional cubic lattice. Using combined Bogoliubo…
Finite-temperature effects on the superfluid Bose-Einstein condensation of confined ultracold atoms in three-dimensional optical lattices
T. P. Polak, T. K. Kopeć
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 optical…
Frustration effects in rapidly rotating square and triangular optical lattices
T. P. Polak, T. K. Kopeć
We discuss the ground state of the two-dimensional Bose-Hubbard (BH) Hamiltonian, relevant for rotating gaseous Bose-Einstein condensates, by employing \mathrm{U}\left(1\right) qua…
Zero-temperature phase diagram of Bose-Fermi gaseous mixtures in optical lattices
T. P. Polak, T. K. Kopeć
We study the ground state phase diagram of a mixture of bosonic and fermionic cold atoms confined on two- and three-dimensional optical lattices. The coupling between bosonic fluct…
Quantum rotor description of the Mott-insulator transition in the Bose-Hubbard model
T. P. Polak, T. K. Kopeć
We present the novel approach to the Bose-Hubbard model using the quantum rotor description. The effective action formalism allows us to formulate a problem in the…