Enhanced fluctuations of the tunneling density of states near bottoms of Landau bands measured by a local spectrometer

TL;DR

This study reveals that local density of states fluctuations in disordered metals are significantly enhanced near the bottoms of Landau bands under strong magnetic fields, highlighting the dominant role of these states affected by disorder.

Contribution

The paper demonstrates the enhanced oscillations of LDOS fluctuations near Landau band bottoms in strong magnetic fields, using a local spectrometer to detect these effects.

Findings

LDOS fluctuations increase with magnetic field strength

Enhanced oscillations are observed compared to standard effects

States near Landau band bottoms dominate the fluctuations

Abstract

We have found that the local density of states fluctuations (LDOSF) in a disordered metal, detected using an impurity in the barrier as a spectrometer, undergo enhanced (with respect to SdH and dHvA effects) oscillations in strong magnetic fields, omega _c\tau > 1. We attribute this to the dominant role of the states near bottoms of Landau bands which give the major contribution to the LDOSF and are most strongly affected by disorder. We also demonstrate that in intermediate fields the LDOSF increase with B in accordance with the results obtained in the diffusion approximation.