Reentrant phase transitions in a quantum spin system with random fields

Abstract

The transverse Ising model with random fields has been studied within the mean-field approximation extended to include quantum effects. When applied random fields are bimodal (sum of two \ensuremath{\delta} functions) and transverse fields \ensuremath{\Gamma} are not too large, tricritical points exist. In these cases, reentrant phenomena can be seen for appropriate ranges of \ensuremath{\Gamma} and random fields ${h}_{0}$.