Resonant tunneling and the quasiparticle lifetime in graphene/boron nitride/graphene heterostructures

TL;DR

This paper investigates how resonant tunneling in graphene/boron nitride/graphene heterostructures reveals detailed information about electron-electron interactions and quasiparticle properties through microscopic calculations of tunneling spectra.

Contribution

It provides a detailed microscopic analysis of tunneling spectra considering quasiparticle lifetime effects, highlighting conditions where electron-electron interactions are observable.

Findings

Resonant tunneling spectra depend on inter-layer bias, temperature, twist angle, and gate voltage.

Electron-electron interactions influence quasiparticle lifetimes and spectral functions.

Parameter regimes are identified where interaction effects are most prominent.

Abstract

Tunneling of quasiparticles between two nearly-aligned graphene sheets produces resonant current-voltage characteristics because of the quasi-exact conservation of in-plane momentum. We claim that, in this regime, vertical transport in graphene/boron nitride/graphene heterostructures carries precious information on electron-electron interactions and the quasiparticle spectral function of the two-dimensional electron system in graphene. We present extensive microscopic calculations of the tunneling spectra with the inclusion of quasiparticle lifetime effects and elucidate the range of parameters (inter-layer bias, temperature, twist angle, and gate voltage) under which electron-electron interaction physics emerges.