Stability of the $N = 2$ bubble states in Corbino geometry under a tilted field

TL;DR

This study investigates the stability of N=2 bubble states in Corbino geometry under tilted magnetic fields, revealing decreasing energy gaps with increased field and discovering a novel bubble state at filling factor 4.67 with unique properties.

Contribution

It provides new experimental insights into the behavior of bubble states under tilted fields and reports a previously unobserved bubble state at filling factor 4.67.

Findings

Energy gaps decrease monotonically with tilt angle.

Magneto-orbital coupling influences the tilt dependence.

Discovery of a bubble state at filling factor 4.67 with high energy gap.

Abstract

We measured the activation energy gap of the N = 2 bubble states using tilted-field technique in two GaAs/AlGaAs samples with Corbino geometry, and observed monotonically decreasing energy gaps with the increasing total magnetic field. The observed tilt angle dependence is discussed based on magneto-orbital coupling and finite-size effect. We also found a bubble state at an uncommon filling factor of 4.67, with an unanticipated energy gap of up to 5.35 K and opposite in-plane field dependence.