Frequency Dependence of Diagonal Resistance in Fractional Quantum Hall Effect via Periodic Modulation of Magnetic Field

TL;DR

This paper investigates how the diagonal resistance in fractional quantum Hall systems depends on the frequency of applied magnetic modulation, revealing a specific relation between the critical frequency and the width of Hall plateaus.

Contribution

It introduces a novel experimental approach using magnetic field modulation to analyze frequency dependence of resistance in FQH states and derives a relation between critical frequency and plateau width.

Findings

Diagonal resistance varies sharply at a specific frequency f0.

The critical frequency f0 relates to the magnetic width dB of Hall plateaus by f0 = e dB / (4 Pi m).

The relation provides insight into the energy gap structure of FQH states.

Abstract

Energy spectrum of fractional quantum Hall (FQH) states is composed of single electron energy (Landau energy) neglecting the Coulomb interactions between electrons, classical Coulomb energy and the quantum energy via quantum transitions. Herein, the sum of the Landau energy and the classical Coulomb energy depends upon the value of the filling factor continuously. However, the quantum transition energy discontinuously depends upon the value of the filling factor. This discontinuity yields energy gaps in many stable FQH states. The energy gaps for specific filling factors produce the precise confinement of Hall resistance. A new experiment is considered as follows; the magnetic strength is fixed to the value to confine the Hall resistance at the filling factor of 2/3 as an example. Moreover the magnetic modulation with frequency f is applied to the system. The frequency dependence of the diagonal resistance is measured. Then, it is shown in this paper that the diagonal resistance varies drastically at some frequency value f0. We clarify the following relation between this value f0 and the magnetic strength width dB of Hall plateaus as f0 = e dB / (4 Pi m), where -e is the charge of electron, Pi =3.141592, and m is the mass of electron.