Quantum Inductance and High Frequency Oscillators in Graphene Nanoribbons

TL;DR

This paper demonstrates that graphene nanoribbons with quantum dots can function as ultra-high frequency oscillators and filters, exhibiting inductive behavior and high Q-factors at frequencies up to hundreds of GHz.

Contribution

It introduces the concept of quantum inductance in graphene nanoribbons and shows their potential as high-frequency electronic components with classical RLC circuit behavior.

Findings

Quantum dots in nanoribbons behave like inductors at >50 GHz.

Device admittance matches classical RLC circuit models.

Resonant frequencies reach up to 900 GHz with high Q-factors.

Abstract

Here we investigate high frequency AC transport through narrow graphene nanoribbons with topgate potentials that form a localized quantum dot. We show that as a consequence of the finite dwell time of an electron inside the quantum dot (QD), the QD behaves like a classical inductor at sufficiently high frequencies \omega\gtrsim50 GHz. When the geometric capacitance of the topgate and the quantum capacitance of the nanoribbon are accounted for, the admittance of the device behaves like a classical serial RLC circuit with resonant frequencies \omega\sim100-900 GHz and Q-factors greater than 10^{6}. These results indicate that graphene nanoribbons can serve as all-electronic ultra-high frequency oscillators and filters thereby extending the reach of high frequency electronics into new domains.