Composite Fermion Geometric Resonance Near {\nu} = 1/2 Fractional Quantum Hall State

TL;DR

This study investigates composite fermion geometric resonances near the { u} = 1/2 fractional quantum Hall state, revealing how the system transitions from a Fermi sea to a correlated quantum Hall state in high-mobility 2D systems.

Contribution

It provides experimental evidence of composite fermion behavior near { u} = 1/2 in high-quality 2D electron and hole systems under periodic potential modulation.

Findings

Observation of geometric resonance features near { u} = 1/2

Measurement of the transition from Fermi sea to fractional quantum Hall state

Evidence supporting the two-component { extPsi}331 state

Abstract

We observe geometric resonance features of composite fermions on the flanks of the even denominator {\nu} = 1/2 fractional quantum Hall state in high-mobility two-dimensional electron and hole systems confined to wide GaAs quantum wells and subjected to a weak, strain-induced, unidirectional periodic potential modulation. The features provide a measure of how close to {\nu} = 1/2 the system stays single-component and supports a composite fermion Fermi sea before transitioning into a {\nu} = 1/2 fractional quantum Hall state, presumably the two-component {\Psi}331 state.