HOPFIELD SPIN-GLASS MODEL IN A TRANSVERSE FIELD

A quantum Hopfield spin-glass model with transverse fields is presente d. A set of equations for the order parameters of a large class of spi n-glass models with transverse fields is obtained, and the phase trans itions are analyzed with a finite number of patterns p. We find that a reentrant phenomenon is possible for a quantum Mattis model with tran sverse fields, contrary to the quantum transverse Sherrington-Kirkpatr ick-like model. The effects of quantum fluctuations (induced by the tr ansverse field) on the ordered phases of systems with competing intera ctions are also discussed.