Composite fermions and parton wavefunctions in twisted graphene on hexagonal boron nitride

TL;DR

This paper investigates the fractional quantum Hall effect in twisted graphene on boron nitride, using a parton model to describe exotic anyonic states with potential quantum computing applications.

Contribution

It introduces a parton wavefunction framework to describe multicomponent FQHE states in twisted graphene, highlighting novel fractional states and their anyonic excitations.

Findings

Observation of FQHE at specific filling factors nu = k/2 and nu = k/3

Identification of composite fermions at nu < 1, including 4/5, 5/7, and 2/3

Proposal of parton states hosting exotic anyons for topological quantum computing

Abstract

In a twisted graphene on hexagonal Boron Nitride, the presence of a gap and the breaking of the symmetry between carbon sublattices leads to multicomponent fractional quantum Hall effect (FQHE) due to the electrons correlation. We report on the FQHE at filling factors nu = k/2 and nu = k/3 with nu > 1, and on the composite fermions at in the nu < 1 lowest landau Level nu = 4/5, 5/7 and 2/3. These fractional states can be described with a partons model, in which the electron is broken down into sub-particles each one residing in an integer quantum Hall effect state; partons are fictitious particles that, glued back together, recover the physical electrons. The parton states host exotic anyons that could potentially form building blocks of a fault-tolerant topological quantum computer.