Superconducting levitation and control of a high-reflectivity micromirror

Authors:Philipp Koller, Jannek J. Hansen, David Walcher, Tomáš Plichta, Rémi Claessen, Martin Žemlička, Philip Schmidt, Rhys G. Povey, Stefan Minniberger, Stefan Putz, Markus Aspelmeyer, Michael Trupke

Abstract:We introduce a method to suspend an optical micromirror, with a total mass of \SI{30}{\micro\gram}, using superconducting magnetic levitation. The micromirror is formed on a silicon membrane, coated with a high-reflectivity dielectric stack and attached to superconducting microspheres. The object is stably levitated inside a magnetic quadrupole field at cryogenic temperatures. Magnetic feedback on the transverse motion is used to stabilize the position of the levitator within the trapping field, allowing to measure the axial displacement of the levitator using optical interferometry. The system reaches a sensitivity of order \SI{100}{\pico\metre/\sqrt{\hertz}} near the axial trap frequency of \SI{167}{Hz}. This approach enables free-standing mirrors with minimal dissipation and tunable oscillation frequencies, offering a platform for precision sensing and quantum cavity optomechanics in the microgram regime.

arXiv:2609.17787 [quant-ph]

(or arXiv:2609.17787v1 [quant-ph] for this version)