Tilt-Induced Phase Transitions in Even-Denominator Fractional Quantum Hall States at the ZnO Interface

TL;DR

This paper investigates phase transitions in even-denominator fractional quantum Hall states in a ZnO quantum well under tilted magnetic fields, revealing a transition from incompressible to compressible states and discussing the absence of the 5/2 state.

Contribution

It introduces a detailed analysis of tilt-induced phase transitions in ZnO quantum wells, including the effects of screened Coulomb potential and proposes wider wells to stabilize certain quantum Hall states.

Findings

Incompressible to compressible phase transition observed with tilt

5/2 state missing in ZnO system

Wider quantum wells may stabilize the 5/2 state

Abstract

Even denominator fractional quantum Hall states in a ZnO quantum well reveal interesting phase transitions in a tilted magnetic field. We have analyzed the planar electron gas in ZnO, confined in a parabolic potential in the third dimension, perpendicular to the plane of the electron gas. Since the Landau level gap is very small in this system we have included the screened Coulomb potential in order to include the effects of all the Landau levels. We observe an incompressible state - compressible state phase transition induced by the tilted field. Additionally, the 5/2 state has been experimentally found to be missing in this system. We however propose that a wider quantum well may help to stabilize the incompressible phase at the 5/2 filling factor.