The p-spin interaction Ising spin glass model in the presence of a transverse field is studied in the large p-limit by means of a convenient operator extension of the cavity fields method avoiding replicas and the Trotter-Suzuki transformation. The results appear quite consistent with those...

The zero-temperature phase transitions in several quantum systems with quenched symmetry-conserving impurities are investigated on the grounds of a diagrammatic approach, starting from an appropriate random quantum field functional Hamiltonian.