Exactly solvable model of a quantum spin glass
Condensed Matter
2009-10-22 v2
Abstract
A mean field spherical model with random couplings between pairs, quartets, and possibly higher multiplets of spins is considered. It has the same critical behavior as the Sherrington-Kirkpatrick model. It thus exhibits replica symmetry breaking. The order parameter function is solved exactly in the whole low temperature phase. The zero field cooled susceptibility remains finite at low . Next a quantum version of the system is considered. Whereas the magnetic properties are not altered qualitatively, the thermodynamics is now regular at small temperatures.
Keywords
Cite
@article{arxiv.cond-mat/9408056,
title = {Exactly solvable model of a quantum spin glass},
author = {Th. M. Nieuwenhuizen},
journal= {arXiv preprint arXiv:cond-mat/9408056},
year = {2009}
}
Comments
4 pages postscript. Revised version, to appear in Phys. Rev. Lett