Pseudo-gap and spin polarization in a two-dimensional electron gas

TL;DR

This paper investigates the pseudo-gap and spin polarization phenomena in a two-dimensional electron gas, explaining experimental observations through a modified exchange interaction model.

Contribution

It introduces an Ising-like exchange interaction model to qualitatively explain the pseudo-gap and spin polarization effects in 2DEG.

Findings

Pseudo-gap observed near Fermi level in 2DEG

Non-monotonic energy dependence on filling factor

Tunneling current anomalies at filling factors 1/2 and 1

Abstract

Tunnelling density of states in the vicinity of Fermi level of a two-dimensional electron gas subjected to an external parallel and zeroth magnetic field is calculated. It reveals a pseudo-gap recently observed in the experiments. The gap originates in spin polarization of 2DEG. Non-monotonic dependence of energy on a Landau level filling factor (density) was obtained. It implies the tunneling current peculiarities at filling factors 1/2 and 1. The Ising-like model of the exchange interaction in 2DEG was exploited instead of the conventional one. It was crucial to achieve even a qualitative agreement with experimental data.