The fundamental 1/f noise in monolayer graphene

TL;DR

This paper derives a fundamental quantum limit on voltage noise in monolayer graphene, showing it is increased by pseudospin/valley effects and matches observed 1/f noise characteristics.

Contribution

It explicitly calculates the quantum bound on voltage noise in graphene, incorporating pseudospin/valley band structure effects, which was not previously done.

Findings

Quantum bound on voltage noise is increased by a factor of 7/2 due to pseudospin/valley effects.

The bound exhibits properties characteristic of 1/f noise.

Dependence on charge carrier density aligns with experimental observations.

Abstract

The quantum indeterminacy caused by non-commutativity of observables at different times sets a lower bound on the voltage noise power spectrum in any conducting material. This bound is calculated explicitly in the case of monolayer graphene. It is found that account of graphene pseudospin/valley band structure raises the quantum bound by a factor of 7/2 compared to the case of spinless charge carriers with a conical energy-momentum dispersion. The bound possesses all characteristic properties of 1/f noise, and its dependence on the charge carrier density is congruent to the experimentally observed.