Tunneling ``zero-bias'' anomaly in the quasi-ballistic regime

TL;DR

This paper investigates the tunneling density of states in an interacting electron gas beyond the diffusive regime, revealing a persistent correction at high energies due to interference effects, challenging traditional theories.

Contribution

It introduces a novel analysis of the DOS correction in the quasi-ballistic regime, extending the understanding beyond the diffusive limit and revising existing theoretical formulas.

Findings

Persistent DOS correction at high energies beyond diffusive limit

Interference between scattered electron waves and Friedel oscillations causes the correction

Revised AAL formula accounting for quasi-ballistic regime effects

Abstract

For the first time, we study the tunneling density of states (DOS) of the interacting electron gas beyond the diffusive limit. A strong correction to the DOS persists even at electron energies exceeding the inverse transport relaxation time, which could not be expected from the well-known Altshuler-Aronov-Lee (AAL) theory. This correction originates from the interference between the electron waves scattered by an impurity and by the Friedel oscillation this impurity creates. Account for such processes also revises the AAL formula for the DOS in the diffusive limit.