Dynamical correlations in the Sherrington-Kirkpatrick model in a transverse field

Abstract

We calculate the real-time-correlation function of the Sherrington-Kirkpatrick spin-glass model in a transverse field. Using a careful analysis of the perturbative expansion of the functional-integral representation, we derive the asymptotic form of the correlation function. In contrast to the previous works, we find for large transverse field a power-law decay of the correlation with time $t$ as $t^{-3/2}$ at zero temperature and $t^{-2}$ at infinite temperature. At the small field region, we also find a significant change in the correlation which comes from the structural difference between two paramagnetic phases.

11 pages, 5 figures; title changed, minor changes

References in corpus (1)

• Quantum fluctuations in the transverse Ising spin glass model: A field theory of random quantum spin systems