The short-range-interaction -random-bond spherical quantum spin glass on the Bethe lattice: dynamic correlations and thermodynamic functions
T K Kopec; K D Usadel
Журнал:
Journal of Physics: Condensed Matter
Дата:
1999-01-25
Аннотация:
We consider the short-range-interaction disordered quantum spherical model with a symmetrical binary -bond distribution on the Bethe lattice (with coordination number z). The system exhibits a quantum phase transition separating the spin-glass and disordered phases, where the quantum effects are regulated by a parameter describing the kinetic energy. The model admits, in the spherical limit, an exact solution both in the spin-glass phase and in the disordered phase. The quantum dynamics is examined via various correlation functions on the infinite tree, which are evaluated in closed form. A closed-form solution for the averaged free energy has been obtained, and various thermodynamic functions are explicitly derived in the form of low-temperature expansions.
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