How do edge states position themselves in a quantum Hall graphene pn junction?

Abstract

Recent experiments have shown that electronic Mach-Zehnder interferometers of unprecedented fidelities could be built using a graphene pn junction in the quantum Hall regime. In these junctions, two different edge states corresponding to two different valley configurations are spatially separated and form the two arms of the interferometer. The observed separation, of several tens of nanometers, has been found to be abnormally high and thus associated to unrealistic values of the exchange interaction. In this work, we show that, although the separation is due to exchange interaction, its actual value is entirely governed by the sample geometry and independent of the value of the exchange splitting. Our analysis follows the lines of the classical work of Chklovski-Shklovskii- Glazman on electrostatically induced edge state reconstruction and includes quantitative numerical calculations in the experimental geometries.

4 pages, 4 figures

References in corpus (5)

• The electronic properties of graphene
• Boron nitride substrates for high-quality graphene electronics
• Direct measurement of the coherence length of edge states in the Integer Quantum Hall Regime
• Electrical control of a solid-state flying qubit
• Valley isospin of interface states in a graphene $pn$ junction in the quantum Hall regime

Cited by in corpus (7)

• Heat equilibration of integer and fractional quantum Hall edge modes in graphene
• Probing valley phenomena with gate-defined valley splitters
• Chiral spin channels in curved graphene $pn$ junctions
• Time-dependent transport in Graphene Mach-Zender Interferometers
• Gate-defined Kondo lattices with valley-helical quantum dot arrays
• Distributed Current Injection into a One-Dimensional Ballistic Edge Channel
• Electrostatics in semiconducting devices I : The Pure Electrostatics Self Consistent Approximation