Quantum Spin Glasses

Heiko Rieger, A. P. Young

Chris R. Laumann, Antonello Scardicchio, Shivaji L. Sondhi

We discuss quantum spin glasses with finite connectivity by presenting an extension of the cavity method used in studies of classical spin glasses.

Heiko Rieger

Nicholas Crawford

ABSTRACT. We study aspects of the thermodynamics of quantum versions of spin glasses. By means of the Lie-Trotter formula for exponential sums of operators, we adapt methods used to analyze classical spin glass models to answer analogous questions about quantum models.

R. N. Bhatt

Zbigniew Domański, T. K. Kopeć, Ferenc Pázmándi +1 more

The infinite-range quantum spin glasses with cubic anisotropy (K) are studied using a combination of the imaginary-time representation with the n-replica approach and the thermofield dynamic method. Mean-field theory phase diagrams in the temperature-anisotropy plane (T,K) are presented for quantum spin numbers S ranging from 2 to 9/2. At T=0, the ground state is nonmagnetic and the spin-glass order is absent for integer spin and large cubic anisotropy, the sign of which depends on S. For half-integer S and sufficiently low temperatures the spin-glass phase persists for arbitrary K.