Geometric interference in a high-mobility graphene annulus p-n junction device

TL;DR

This paper reports the observation of geometric interference patterns in a high-mobility graphene annulus p-n junction device, attributed to quantum scarring, independent of temperature and magnetic field effects.

Contribution

It identifies quantum scarring as the likely origin of geometric interference in graphene annulus devices, distinguishing it from other known interference phenomena.

Findings

Resistance patterns are independent of temperature and magnetic field.

Patterns are not due to Aharonov-Bohm, Fabry Perot, or moiré effects.

Quantum scarring is proposed as the source of interference.

Abstract

The emergence of interference is observed in the resistance of a graphene annulus pn junction device as a result of applying two separate gate voltages. The observed resistance patterns are carefully inspected, and it is determined that the position of the peaks resulting from those patterns are independent of temperature and magnetic field. Furthermore, these patterns are not attributable to Aharonov-Bohm oscillations, Fabry Perot interference at the junction, or moir\'e potentials. The device data are compared with those of another device fabricated with a traditional Hall bar geometry, as well as with quantum transport simulation data. Since the two devices are of different topological classes, the subtle differences observed in the corresponding measured data indicate that the most likely source of the observed geometric interference patterns is quantum scarring.