Probing a two-dimensional Fermi surface by tunneling

Abstract

Equilibrium tunneling between parallel two-dimensional electron systems is measured as a function of in-plane magnetic field and sheet density. For equal two-dimensional densities the tunnel conductance is sharply peaked around zero field, but varies slowly at intermediate fields. Around 6 T the conductance exhibits a weaker peak followed by an abrupt drop to zero. A simple model of two displaced, but intersecting, Fermi circles explains these results.