Dephasing time in graphene due to interaction with flexural phonons

TL;DR

This paper studies how flexural phonons in graphene cause electron dephasing, revealing unique temperature and density dependencies that can help identify phonon effects via electronic transport measurements.

Contribution

It provides a detailed analysis of electron dephasing due to flexural phonons in graphene, including regimes where standard golden rule approaches fail, and predicts distinctive temperature and density behaviors.

Findings

Dephasing rate can be comparable to electron-electron interactions.

Temperature dependence crosses over from T^2 to T with increasing T.

Dephasing rate varies non-monotonously with electron density.

Abstract

We investigate decoherence of an electron in graphene caused by electron-flexural phonon interaction. We find out that flexural phonons can produce dephasing rate comparable to the electron-electron one. The problem appears to be quite special because there is a large interval of temperature where the dephasing induced by phonons can not be obtain using the golden rule. We evaluate this rate for a wide range of density ($n$) and temperature ($T$) and determine several asymptotic regions with temperature dependence crossing over from $\tau_{\phi }^{-1}\sim T^{2}$ to $\tau_{\phi}^{-1}\sim T$ when temperature increases. We also find $\tau_{\phi}^{-1}$ to be a non-monotonous function of $n$. These distinctive features of the new contribution can provide an effective way to identify flexural phonons in graphene through the electronic transport by measuring the weak localization corrections in magnetoresistance.