Levitated Magnets for Quantum Metrology

Levitating micromagnets have been proposed theoretically as building blocks for a range of hybrid quantum systems and as extremely low-noise sensors of torque, force, or magnetic field that can far outperform conventional quantum-limited devices in terms of energy resolution. This outstanding potential is supported by recent breakthrough experiments, but is far from being fully demonstrated. In this project, we aim at a systematic investigation of sensors based on levitated micromagnets. Different levitation platforms will be explored, such as superconducting traps based on the Meissner effect, on-chip circuits for magnetic traps, free-fall and Paul traps for charged micromagnets, and use coupling with different quantum systems or devices, such as diamond-nitrogen vacancies (NV) and SQUIDs. Primarily, the librational and rotational motion of the levitated magnets will be studied with a focus on detecting ultralow torques and magnetic fields, with the goal of demonstrating unprecedented energy resolution. In particular, the most sensitive region corresponding to the atom-like Larmor precession of a mesoscopic magnet, a special effect arising from the quantum nature of intrinsic spin, will be re-forged. To accomplish this, the microgravity of the Einstein-Elevator is used, where the Larmor precession of a freely falling magnet can be observed in the cleanest way imaginable.