DYNAMICS OF THE INFINITE-RANGE ISING SPIN-GLASS MODEL IN A TRANSVERSEFIELD

We use quantum Monte Carlo methods and various analytic approximations to study the infinite-range Ising spin-glass model in a transverse fi eld in the disordered phase. We focus on the behavior of the frequency dependent susceptibility of the system above and below the critical f ield. We establish that, at the quantum critical point, there exists a n equivalence between the long-time behavior of this model and that of the single-impurity Kondo model. Our predictions for the long-time dy namics of the model are in good agreement with experimental results on LiHo0.167Y0.833F4. [S0031-9007(98)07212-3].