Tricritical Behavior of Ising Spin Glasses with Charge Fluctuations

We show that tricritical points displaying unusual behavior exist in phase diagrams of fermionic Ising spin glasses as the chemical potential or the filling assumes characteristic values. Exact results for infinite range interaction and a one-loop renormalization group analysis of thermal tricritical fluctuations for finite range models are presented. Surprising similarities with zero temperature transitions and a new $T=0\mathrm{}$ tricritical point of metallic quantum spin glasses are derived.