This work was supported in part by the European Union Horizon Europe 2021–2027 framework program under Grant Agreement No. 101080143 (SuperMeQ), the QuantERA project C'MON-QSENS!, the Knut and Alice Wallenberg Foundation through a Wallenberg Academy Fellowship (W.W.), by the Wallenberg Center for Quantum Technology (WACQT, A.P.), by the Chalmers Excellence Initiative Nano, and by the Swedish Research Council (Grant No. 2020-00381, G.H.). Sample fabrication was performed in the Myfab Nanofabrication Laboratory at Chalmers. Simulations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at Tetralith, Linköping University, partially funded by the Swedish Research Council (Grant No. 2018-05973).

Data and code for the article "Superconducting microsphere magnetically levitated in an anharmonic potential", consisting of all the measurements, spectra and code for data analysis.