Abstract
An infinite-range quantum Ising spin glass with cubic anisotropy (K) is studied using 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) for quantum spins S ranging from 2 to 9/2 are presented. For integer-spin values and large cubic anisotropy (positive or negative, depending on S) a condensation into a nonmagnetic spin state occurs, accompanied by the destruction of the spin-glass order as indicated by the finite critical value (T=0). For half-integer S and sufficiently low temperature the spin-glass phase persists for arbitrary K.
- Received 6 October 1993
DOI:https://doi.org/10.1103/PhysRevB.49.3378
©1994 American Physical Society