Theory of plasmon spectroscopy with the quantum twisting microscope

TL;DR

This paper develops a theoretical framework for using the quantum twisting microscope to analyze plasmon excitations in twisted bilayer graphene through inelastic tunneling spectroscopy, revealing how twist angle and bias influence plasmon features.

Contribution

It introduces a general theoretical approach for inelastic tunneling spectroscopy of collective electronic excitations with the quantum twisting microscope, applied specifically to twisted bilayer graphene.

Findings

Predicted plasmon features in tunneling spectra of TBG near the magic angle.

Established the dependence of differential conductance on twist angle and bias.

Provided insights into plasmon-electron interactions in TBG.

Abstract

We consider plasmon-assisted electron tunneling in a quantum twisting microscope (QTM). The dependence of the differential conductance on the two control parameters of the QTM -- the twist angle and bias -- reveals the plasmon spectrum as well as the strength of plasmon-electron interactions in the sample. We perform microscopic calculations for twisted bilayer graphene (TBG), to predict the plasmon features in the tunneling spectra of TBG close to the magic angle for different screening environments. Our work establishes a general framework for inelastic tunneling spectroscopy of collective electronic excitations using the quantum twisting microscope.