Tunneling into a Two-Dimensional Electron Liquid in a Weak Magnetic Field

TL;DR

This paper investigates the spectral density of a two-dimensional electron liquid in a weak magnetic field, revealing a low-energy gap influenced logarithmically by interaction strength, with considerations of temperature and disorder effects.

Contribution

Develops a hydrodynamic model to analyze low-energy excitations and uncovers a persistent low-energy gap in the density of states at high filling factors.

Findings

Density of states exhibits a low-energy gap at high filling factors

Gap width depends logarithmically on interaction strength

Temperature and disorder effects on the density of states are discussed

Abstract

We study the spectral density function of a two-dimensional electron liquid in a weak magnetic field, the filling factor $\nu\gg 1$. A hydrodynamic model for low-energy excitations of the liquid is developed. It is found that even at $\nu\gg 1$ the density of states exhibits a gap at low energies. Its width $2E_0$ depends on the strength of interaction only logarithmically, $2E_0=(\hbar\omega_c/\nu)\ln (\nu e^2/\varepsilon\hbar v_F)$. The effects of temperature and disorder on the density of states are discussed.