Fermionic Heisenberg Glasses with BCS Pairing Interaction

Abstract

We have analyzed a fermionic infinite-ranged quantum Heisenberg spin glass with BCS coupling in real space in the presence of a magnetic field. It has been possible to locate the transition line between the normal paramagnetic phase (NP) and the phase where there is a long range order corresponding to pair formation in sites (PAIR). The nature of the transition line is also investigated. This transition ends at Tf, the transition temperature between NP and spin glass phase (SG) where the static approximation and replica symmetry ansatz are reliable.