Effects of two dimensional plasmons on the tunneling density of states

TL;DR

This paper investigates how gapless plasmons affect the tunneling density of states in a 2D electron gas and explores similar effects in composite fermion metals under magnetic fields, with implications for quantum Hall experiments.

Contribution

It demonstrates a universal correction to the tunneling density of states caused by gapless plasmons in 2D electron systems and discusses its relevance to quantum Hall phenomena.

Findings

Universal linear correction to tunneling density of states in 2D electron gas.

Potential explanation for deviations in quantum Hall tunneling experiments.

Extension of plasmon effects to composite fermion metals under magnetic fields.

Abstract

We show that gapless plasmons lead to a universal $(\delta\nu(\epsilon)/\nu\propto |\epsilon|/E_F)$ correction to the tunneling density of states of a clean two dimensional Coulomb interacting electron gas. We also discuss a counterpart of this effect in the "composite fermion metal" which forms in the presence of a quantizing perpendicular magnetic field corresponding to the half-filled Landau level. We argue that the latter phenomenon might be relevant for deviations from a simple scaling observed by A.Chang et al in the tunneling $I-V$ characteristics of Quantum Hall liquids.