Phonon mediated interlayer conductance in twisted graphene bilayers

TL;DR

This paper demonstrates that phonon scattering significantly enhances interlayer conductance in twisted graphene bilayers, revealing orientation-dependent behaviors and diode-like effects at low temperatures, with implications for device applications.

Contribution

It introduces a phonon-mediated mechanism for interlayer conduction in twisted graphene bilayers, challenging previous assumptions about momentum conservation suppression.

Findings

Phonon scattering facilitates interlayer conductance in twisted bilayers.

Conductance depends on temperature, doping, rotation angle, and bias voltage.

Low-temperature diode-like current-voltage characteristics are predicted.

Abstract

Conduction between graphene layers is suppressed by momentum conservation whenever the layer stacking has a rotation. Here we show that phonon scattering plays a crucial role in facilitating interlayer conduction. The resulting dependence on orientation is radically different than previously expected, and far more favorable for device applications. At low temperatures, we predict diode-like current-voltage characteristics due to a phonon bottleneck. Simple scaling relationships give a good description of the conductance as a function of temperature, doping, rotation angle, and bias voltage, reflecting the dominant role of the interlayer beating phonon mode.