Quantum Superposition States of Two Valleys in Graphene

TL;DR

This paper explores how quantum superpositions of valley states in graphene alter the properties of Dirac fermions, revealing novel behaviors and proposing experimental detection methods.

Contribution

It demonstrates that superpositions of valley states in graphene significantly change fermion properties and suggests a way to generate and detect these states.

Findings

Superposition states exhibit oddball behaviors in chiral tunneling.

Line defects can generate valley superpositions.

Proposed device for detecting relativistic superposition states.

Abstract

A system in a quantum superposition of distinct states usually exhibits many peculiar behaviors. Here we show that putting quasiparticles of graphene into superpositions of states in the two valleys can complete change the properties of the massless Dirac fermions. Due to the coexistence of both the quantum and relativistic characteristics, the superposition states exhibit many oddball behaviors in their chiral tunneling process. We further demonstrate that a recently observed line defect in graphene could be used to generate such superposition states. A possible experimental device to detect the novel behaviors of the relativistic superposition states in graphene is proposed.