Quantum and classical confinement of resonant states in a trilayer graphene Fabry-Perot interferometer

TL;DR

This paper demonstrates how trilayer graphene can be used to control resonant electronic states and conductance oscillations through phase coherence, pseudospin manipulation, and magnetic fields, highlighting its potential for electron optics.

Contribution

It introduces a method to cloak resonant states in trilayer graphene, enabling control over conductance oscillations via classical and quantum pseudospin techniques.

Findings

Giant conductance oscillations observed in trilayer graphene Fabry-Perot interferometers.

Cloaking of resonant states suppresses conductance oscillations.

Magnetic field and pseudospin manipulation achieve selective control of electron transport.

Abstract

The advent of few-layer graphenes has given rise to a new family of two-dimensional systems with emergent electronic properties governed by relativistic quantum mechanics. The multiple carbon sublattices endow the electronic wavefunctions with pseudospin, a lattice analog of the relativistic electron spin, while the multilayer structure leads to electric field effect tunable electronic bands. Here we use these properties to realize giant conductance oscillations in ballistic trilayer graphene Fabry-Perot interferometers, which result from phase coherent transport through resonant bound states beneath an electrostatic barrier. We cloak these states by selectively decoupling them from the leads, resulting in transport via non-resonant states and suppression of the giant oscillations. Cloaking is achieved both classically, by manipulating quasiparticle momenta with a magnetic field, and quantum mechanically, by locally varying the pseudospin character of the carrier wavefunctions. Our results illustrate the unique potential of trilayer graphene as a versatile platform for electron optics and pseudospintronics.