Exact Diagonalization Study of an Extended Hubbard Model for a Cubic Cluster at Quarter Filling

Abstract

In the paper the thermodynamics of a cubic cluster with 8 sites at quarter filling is characterized by means of exact diagonalization technique. Particular emphasis is put on the behaviour of such response functions as specific heat and magnetic susceptibility. The system is modelled with extended Hubbard model which includes electron hopping between both first and second nearest neighbours as well as coulombic interactions, both on-site and between nearest-neighbour sites. The importance of hopping between second nearest neighbours and coulombic interactions between nearest neighbours for the temperature dependences of thermodynamic response functions is analysed. In particular, the predictions of Schottky model are compared with the calculations based on the full energy spectrum.

To appear in Proceedings of CSMAG'16 conference

References in corpus (2)

• The Schottky-type specific heat as an indicator of relative degeneracy between ground and first-excited states: the case study of regular Ising polyhedra
• Analytical solution of a Hubbard model extended by nearest neighbour Coulomb and exchange interaction on a triangle and tetrahedron

Cited by in corpus (4)

• Supersolid-Superfluid phase separation in the extended Bose-Hubbard model
• Hubbard pair cluster in the external fields. Studies of the polarization and susceptibility
• Hubbard pair cluster in the external fields. Studies of the magnetic properties
• Hubbard pair cluster with elastic interactions. Studies of thermal expansion, magnetostriction and electrostriction