Tunneling Conductance Between Parallel Two Dimensional Electron Systems

TL;DR

This paper develops a theoretical framework to calculate the low-temperature dc tunneling conductance between parallel two-dimensional electron systems, accounting for disorder effects and impurity scattering.

Contribution

It provides a new linear-response and impurity-averaged perturbation theory approach to analyze tunneling conductance, including disorder broadening effects and impurity correlations.

Findings

Disorder broadening affects tunneling features depending on electron lifetime and impurity scattering.

Vertex corrections are significant only at weak magnetic fields and high impurity correlations.

Tunneling measurements can potentially determine electron lifetimes in quantum wells.

Abstract

We derive and evaluate expressions for the low temperature {\it dc} equilibrium tunneling conductance between parallel two-dimensional electron systems. Our theory is based on a linear-response formalism and on impurity-averaged perturbation theory. The disorder broadening of features in the dependence of tunneling conductance on sheet densities and in-plane magnetic field strengths is influenced both by the finite lifetime of electrons within the wells and by non-momentum-conserving tunneling events. Disorder vertex corrections are important only for weak in-plane magnetic fields and strong interwell impurity-potential correlations. We comment on the basis of our results on the possibility of using tunneling measurements to determine the lifetime of electrons in the quantum wells.