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arXiv · 2401.08854

Remote sensing of a levitated superconductor with a flux-tunable microwave cavity

Philip Schmidt·Remi Claessen·Gerard Higgins·Joachim Hofer·Jannek J. Hansen·Peter Asenbaum·Kevin Uhl·Reinhold Kleiner·Rudolf Gross·Hans Huebl·Michael Trupke·Markus Aspelmeyer
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Abstract

We present a cavity-electromechanical system comprising a superconducting quantum interference device which is embedded in a microwave resonator and coupled via a pick-up loop to a 6 $\mu$g magnetically-levitated superconducting sphere. The motion of the sphere in the magnetic trap induces a frequency shift in the SQUID-cavity system. We use microwave spectroscopy to characterize the system, and we demonstrate that the electromechanical interaction is tunable. The measured displacement sensitivity of $10^{-7} \, \mathrm{m} / \sqrt{\mathrm{Hz}}$, defines a path towards ground-state cooling of levitated particles with Planck-scale masses at millikelvin environment temperatures.

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Philip Schmidt, Remi Claessen, Gerard Higgins, Joachim Hofer, Jannek J. Hansen, Peter Asenbaum, Kevin Uhl, Reinhold Kleiner, Rudolf Gross, Hans Huebl, Michael Trupke, Markus Aspelmeyer. 2024-01-16. Remote sensing of a levitated superconductor with a flux-tunable microwave cavity. https://doi.org/10.1103/physrevapplied.22.014078

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