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arXiv · 2210.13451

Superconducting microsphere magnetically levitated in an anharmonic potential with integrated magnetic readout

Martí Gutierrez Latorre·Gerard Higgins·Achintya Paradkar·Thilo Bauch·Witlef Wieczorek
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Abstract

Magnetically levitated superconducting microparticles offer a promising path to quantum experiments with picogram to microgram objects. In this work, we levitate a 700ng $\sim 10^{17}$amu superconducting microsphere in a magnetic chip trap in which detection is integrated. We measure the particle's center-of-mass motion using a DC-SQUID magnetometer. The trap frequencies are continuously tunable between 30 and 160 Hz and the particle remains stably trapped over days in a dilution refrigerator environment. We characterize motional-amplitude-dependent frequency shifts, which arise from trap anharmonicities, namely Duffing nonlinearities and mode couplings. We explain this nonlinear behavior using finite element modelling of the chip-based trap potential. This work constitutes a first step towards quantum experiments and ultrasensitive inertial sensors with magnetically levitated superconducting microparticles.

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Martí Gutierrez Latorre, Gerard Higgins, Achintya Paradkar, Thilo Bauch, Witlef Wieczorek. 2022-10-24. Superconducting microsphere magnetically levitated in an anharmonic potential with integrated magnetic readout. https://doi.org/10.1103/physrevapplied.19.054047

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