Graphene Josephson Junctions for Engineering Motional Quanta

TL;DR

This paper introduces a hybrid quantum device using graphene Josephson junctions that enables strong, tunable coupling between mechanical vibrations and superconducting circuits, facilitating advanced quantum state control and sensing.

Contribution

It presents a novel graphene-based hybrid quantum device leveraging flexural mode coupling for efficient quantum state manipulation and sensing.

Findings

Strong, tunable coupling at zero-point fluctuations

Efficient generation of non-classical mechanical states

Enhanced quantum sensing capabilities

Abstract

We propose a hybrid quantum device based on the graphene Josephson junctions, where the vibrational degrees of freedom of a graphene membrane couple to the superconducting circuits. The flexural mode-controlled tunneling of the Cooper pairs introduces a strong and tunable coupling even at the zero-point fluctuations level. By employing this interaction, we show that a parametric process can be efficiently implemented. We then investigate foundational and technological applications of our hybrid device empowered by nonlinear interactions, with fast generation of non-classical mechanical states, and critically enhanced quantum sensing under suitable quantum control. Our work provides the possibility of employing the graphene motional degree of freedom for quantum information processing in circuit quantum nanomechanical structures.