SIMULATION OF THE MAGNETIC STRUCTURE UPON ORDERING EG ORBITALSTO THE QUASI-ONE- AND QUASI-TWO-DIMENSIONAL MAGNETSBY QUANTUM MONTE CARLO METOD

The exchange mechanism influence on the electrons ordering on eg orbitals in a chain and in a two-dimensional Heisenberg model with exchange anisotropy for a S = 1/2 spin is determined by a quantum Monte Carlo method. The existence regions of a long-range quasi-one- and two-dimensional antiferromagnetic order with the special exchange topology are determined. The plateau existence region in the field dependence of magnetization, as well as the wave vector of the magnetic structure modulation with Q = p/2 in the (magnetic field - exchange alternating) plane, is determined.

alternation of exchange, orbital and magnetic ordering, stripes