Properties of Quantum XY Spin Glass in Longitudinal Field

By using the generalized static replica symmetry approximation, the quantum XY spin-glass model in a longitudinal field is investigated. The thermodynamic quantities, spin-glass and self-interaction order parameters are calculated numerically. The local susceptibility depending on temperature has the typical spin-glass plateau characteristic; the specific heat against temperature display a crossover feature which was discovered experimentally in the CuMn sample by Brodale et al. (J. Magn. Magn. Mater. 31-34 (1983) 1331) and cusps sharper than that in the model with the Dzyaloshinskii-Moriya interaction.