Broken Symmetry Quantum Hall States in Dual Gated ABA Trilayer Graphene

TL;DR

This study investigates quantum Hall states in dual-gated ABA trilayer graphene, revealing degeneracy lifting and electric field-induced transitions, highlighting complex interaction effects in this material.

Contribution

It provides experimental evidence of degeneracy breaking and electric field control of quantum Hall states in ABA trilayer graphene, supported by tight-binding calculations.

Findings

Observation of quantum Hall plateaus at multiple filling factors

Degeneracy lifting of Landau levels under magnetic field

Electric field-induced transitions between quantum Hall states

Abstract

We present low temperature transport measurements on dual-gated suspended trilayer graphene in the quantum Hall (QH) regime. We observe QH plateaus at filling factors {\nu}=-8, -2, 2, 6, and 10, in agreement with the full-parameter tight binding calculations. In high magnetic fields, odd-integer plateaus are also resolved, indicating almost complete lifting of the 12-fold degeneracy of the lowest Landau levels (LL). Under an out-of-plane electric field E, we observe degeneracy breaking and transitions between QH plateaus. Interestingly, depending on its direction, E selectively breaks the LL degeneracies in the electron-doped or hole-doped regimes. Our results underscore the rich interaction-induced phenomena in trilayer graphene.