Optical interferometric readout of a magnetically levitated superconducting microsphere

Physical Review Applied 2026 Open access

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Authors: Jannek J. Hansen, Stefan Minniberger, Dominik Ilk, Peter Asenbaum, Gerard T. Higgins, Rhys G. Povey, Philip Schmidt, Joachim Hofer, Remi Claessen, Markus Aspelmeyer, Michael Trupke
DOI: 10.1103/ljxp-3f66
Cited by: 1
References: 57

Abstract

We probe the motion of a 6- μ g magnetically levitated superconducting microsphere using optical interferometry at 3 K , achieving a resolution of the order of 1 nm / Hz , and use the measured signal to feedback-cool its motion. The resolution exceeds the shot-noise limit of 11 pm / Hz primarily due to technical noise arising from the roughness of the particle, in combination with its free rotation. These measurements demonstrate that the combination of interferometric optical readout and superconducting magnetic levitation, together with established techniques of cavity optomechanics, provides all the ingredients required for quantum physics experiments with microgram masses.

Fields of Study & Subjects

Mechanical and Optical Resonators Near-Field Optical Microscopy Characterization and Applications of Magnetic Nanoparticles

Publication details

Journal / source
Physical Review Applied
Publisher
American Physical Society (APS)
Volume
25
Issue
4
Publication date
27 March 2026
Language
EN