Magnetoconductance Oscillations in High-Mobility Suspended Bilayer and Trilayer Graphene

TL;DR

This paper reports the observation of pronounced magnetoconductance oscillations in high-mobility suspended bilayer and trilayer graphene, revealing features suggestive of symmetry breaking and fractional quantum Hall states.

Contribution

It presents experimental evidence of magnetoconductance oscillations and fractional quantum Hall features in high-mobility suspended graphene layers, highlighting new quantum phenomena.

Findings

Conductance minima at all integer filling factors between 0 and -8 in bilayer graphene.

Observation of features at fractional and integer filling factors in trilayer graphene.

Persistence of these features up to 4.5K at 8T magnetic field.

Abstract

We report pronounced magnetoconductance oscillations observed on suspended bilayer and trilayer graphene devices with mobilities up to 270,000 cm2/Vs. For bilayer devices, we observe conductance minima at all integer filling factors nu between 0 and -8, as well as a small plateau at {\nu}=1/3. For trilayer devices, we observe features at nu=-1, -2, -3 and -4, and at {\nu}~0.5 that persist to 4.5K at B=8T. All of these features persist for all accessible values of Vg and B, and could suggest the onset of symmetry breaking of the first few Landau (LL) levels and fractional quantum Hall states.