Short-range ±J interaction Ising spin glass in a transverse field on a Bethe lattice:: a quantum-spherical approach

We consider the short-range interaction disordered quantum Ising model with symmetric binary +/- J bond distribution on the Bethe lattice (with coordination number z). The system exhibits quantum phase transition separating the spin glass and disordered phases where the quantum effect are regulated by a parameter A describing the transverse field. By introducing a mapping of the quantum Hamiltonian of the model onto a soft-spin action we consider it truncated version in a form of the solvable quantized spherical model. Quantum dynamics is examined via various correlation functions on the infinite tree which are evaluated in a closed form. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.