Fermionic TAP-equations

Abstract

We derive the TAP equations for the fermionic Ising spin glass. It is found that, just as in the non-fermionic model, the conditions for stability and for validity of the free energy are equivalent. We determine the breakdown of the paramagnetic phase. Numeric solutions of the fermionic TAP-equations at T=0 allowed to localize a first order transition between the spin glass phase and the paramagnetic phase at $μ\approx 0.8$. We computed at zero temperature the filling factor $ν(μ)$ and the distribution of internal fields. The saddle-point equations resulting from the calculation of the number of solutions to the TAP-equations were found to be much more complicated as in the non-fermionic case.