|
Journal of Physical Studies 5(3/4), 268–278 (2001)
DOI: https://doi.org/10.30970/jps.05.268 PHASE TRANSITIONS IN PSEUDOSPIN-ELECTRON MODEL AT WEAK COUPLINGI. V. Stasyuk, T. S. Mysakovych
Institute for Condensed Matter Physics of the National Academy of Science
of Ukraine, |
 |
The thermodynamically equilibrium states and phase transitions in the pseudospin-electron model with the transverse field are studied in the weak coupling approximation. In the regime of the constant chemical potential the possibility of the first-order phase transitions between uniform phases as well as the first- or the second-order transitions into phase with the doubled lattice period is established depending on the value of $μ$. The conditions of appearance of the phase separation in the system at the given average electron concentration are analysed. Studied in the paper is also the influence of the transverse field (which is connected with the tunneling-like splitting) on the phase transitions and the conditions of their realization. The phase diagrams are built at the various electron densities of states in the conduction band.
PACS number(s): 63.20.Ry, 64.70.Kb, 71.10.Fd, 77.80.Bh