Anomalous quantum Hall conductivity and resonances in coupled layers

TL;DR

This paper investigates a coupled two-layer quantum Hall system, revealing deviations from quantized Hall conductivity and predicting negative jumps at Landau level resonances, with results stable against disorder.

Contribution

It introduces the analysis of Landau level resonances in coupled layers, showing non-quantized Hall effects and negative jumps, which are robust against disorder.

Findings

Deviations from quantized Hall conductivity at Landau level resonances

Prediction of negative jumps in Hall conductivity

Robustness of results against disorder

Abstract

A two-layer system coupled via tunneling and with different carrier masses in each layer is investigated in the integer quantum Hall regime. Striking deviations of the one-layer Hall conductivity from the usual quantization are found, if resonance between Landau levels of different layers is achieved. The appearance of negative jumps in the Hall conductivity is also predicted under suitable conditions. The results obtained are robust against disorder in the system.