Strong Single-Photon Coupling in Superconducting Quantum Magnetomechanics

TL;DR

This paper demonstrates that superconducting microcantilevers can achieve strong single-photon coupling with microwave circuits through flux-dependent inductive interactions, enabling advances in quantum magnetomechanics.

Contribution

It introduces a novel method to attain strong single-photon coupling using a superconducting strip and flux-dependent circuits, with feasible experimental parameters.

Findings

Achieved strong single-photon magnetomechanical coupling regime.

Enhanced coupling via diamagnetism and demagnetizing effects.

Proposed experimental setup with superconducting strip and flux pickup coil.

Abstract

We show that the inductive coupling between the quantum mechanical motion of a superconducting microcantilever and a flux-dependent microwave quantum circuit can attain the strong single-photon nanomechanical coupling regime with feasible experimental parameters. We propose to use a superconducting strip, which is in the Meissner state, at the tip of a cantilever. A pick-up coil collects the flux generated by the sheet currents induced by an external quadrupole magnetic field centered at the strip location. The position-dependent magnetic response of the superconducting strip, enhanced by both diamagnetism and demagnetizing effects, leads to a strong magnetomechanical coupling to quantum circuits.