Selective focusing of electrons and holes in a graphene-based superconducting lens

TL;DR

This paper demonstrates that a graphene pnp junction with a superconducting electrode can act as a Veselago lens, focusing electrons and holes into different points, which could aid in detecting entangled electron pairs.

Contribution

It introduces a novel graphene-based superconducting lens that selectively focuses electrons and holes, confirmed by microscopic calculations and robust under various conditions.

Findings

Focusing pattern persists despite deviations from ideal conditions

The lens can spatially separate electrons and holes

Potential application in entangled electron pair detection

Abstract

We show that a graphene pnp junction with a central superconducting electrode acts as a Veselago lens for incoming electrons by focusing them and their phase-conjugated counterpart (holes) into different points of the optical axis. This selective focusing suggested by a simple trajectory analysis is confirmed by fully microscopic calculations. Although the focusing pattern is degraded by deviations from the ideal conditions we show that it remains visible for a wide range of parameters. We discuss how this property can be useful for the detection of entangled electron pairs.