Two-dimensional electron system in high magnetic fields: Wigner crystal vs. composite-fermion liquid

TL;DR

This paper investigates the phase transition in a two-dimensional electron system under high magnetic fields, revealing how minor energy corrections can switch the ground state between a Wigner crystal and a composite-fermion liquid, clarifying experimental ambiguities.

Contribution

It demonstrates that small energy corrections in composite fermion interactions can fundamentally alter the ground state, explaining recent experimental observations.

Findings

Small energy corrections (<1%) significantly impact the ground state.

The phase transition between Wigner crystal and composite-fermion liquid is sensitive to minor energy differences.

Theoretical insights reconcile conflicting experimental results.

Abstract

The two dimensional system of electrons in a high magnetic field offers an opportunity to investigate a phase transition from a quantum liquid into a Wigner solid. Recent experiments have revealed an incipient composite fermion liquid in a parameter range where theory and many experiments had previously suggested the Wigner crystal phase, thus calling into question our current understanding. This Letter shows how very small quantitative corrections (< 1%) in the energy due to the weak interaction between composite fermions can cause a fundamental change in the nature of the ground state, thus providing insight into the puzzling experimental results.