Jacek Wojtkiewicz

Ground states of the Falicov-Kimball model with correlated hopping

Two-dimensional spinless Falicov-Kimball model (FKM) with correlated hopping is studied perturbatively in the limit of large on-site Coulomb interaction

Some properties of frustrated spin systems: extensions and applications of Lieb-Schupp approach

U

Stability of Ground States of 2d Strongly Asymmetric Correlated-Hopping Hubbard Model

. In the neutral case the effective Hamiltonian in spin variables is derived up to terms proportional to

Operator Reflection Positivity Inequalities and their Applications to Interacting Quantum Rotors

U^{-3}

On the phase diagram of the anisotropic XY chain in transverse magnetic field

. Unlike the simplest FKM case, it contains odd parity terms (resulting from the correlated hopping) in addition to even parity ones. The ground-state phase diagram of the effective Hamiltonian is examined in the

Absence of orderings in Hubbard models

(a/t, h)

Towards designing polymers for photovoltaic applications: A DFT and experimental study of polyazomethines with various chemical structures

plane, where

Bogolyubov inequality for the ground state and its application to interacting rotor systems

a/t

Distribution of Energies for the Two-Dimensional Ising Model

is a parameter characterizing strength of the correlated hopping and

New environmentally friendly polyazomethines with thiophene rings for polymer solar cells

h