Quantum XY Spin Glass with Ferromagnetic Coupling in External Field

The quantum XY spin glass model with ferromagnetic coupling in an external field is investigated numerically. The susceptibility exhibits the typical spin glass feature, the cusp of the transverse susceptibility corresponding to the phase transition is shifted to lower temperature by increasing field. In addition to the crossover feature observed in CuMn, the specific heat exhibits the 2-dimensional Ising model-like feature.