TRICRITICAL BEHAVIOR OF ISING SPIN-GLASSES WITH CHARGE FLUCTUATIONS

We show that tricritical points displaying unusual behavior exist in p hase diagrams of fermionic Ising spin glasses as the chemical potentia l or the filling assumes characteristic values. Exact results for infi nite range interaction and a one-loop renormalization group analysis o f thermal tricritical fluctuations for finite range models are present ed. Surprising similarities with zero temperature transitions and a ne w T = 0 tricritical point of metallic quantum spin glasses are derived .