Anomalous behavior of 1/f noise in graphene near the charge neutrality point

TL;DR

This paper studies the unusual 1/f noise behavior in graphene near the charge neutrality point, revealing bias-dependent anomalies and proposing electron-hole puddle depinning as a key mechanism.

Contribution

It uncovers the anomalous dependence of 1/f noise on bias voltage in graphene and links it to electron-hole puddle dynamics near charge neutrality.

Findings

1/f noise deviates from Hooge relation near charge neutrality

Anomalous noise behavior is bias-dependent

Depinning of electron-hole puddles explains the noise anomaly

Abstract

We investigate the noise in single layer graphene devices from equilibrium to far from equilibrium and found that the 1/f noise shows an anomalous dependence on the source-drain bias voltage (VSD). While the Hooge relation is not the case around the charge neutrality point, we found that it is recovered at very low VSD region. We propose that the depinning of the electron-hole puddles is induced at finite VSD, which may explain this anomalous noise behavior.