Testing quantum physics in uncharted territory using a magneto-mechanical oscillator

Research Project, 2020 – 2023

Quantum physics exquisitely describes our Universe at its smallest scales, but it is still unclear how the transition from the quantum world to our classical macroscopic world happens. It is also unclear how to incorporate effects of gravity into quantum mechanics. To get experimental insights into these problems, we need to be able to study quantum physics in systems with larger masses whose wavefunctions are spread over larger distances. A magnetically-levitated superconducting microsphere is a promising system for doing this. In this project I will develop this novel system and use it to probe quantum physics in an uncharted regime, with a microsphere of mass 1013 atomic mass units whose wavefunction is spread over 1pm. During the first 27 months I will develop techniques to bring this new system to the quantum regime at the University of Vienna. Quantum systems must be isolated from their surroundings, so the microsphere will be magnetically levitated away from surfaces, in an extreme high vacuum at a cryogenic temperature. The microsphere’s motion will be controlled via magnetic coupling to superconducting circuits. This will enable cooling to the ground state and preparation of quantum states of motion. During the final 9 months I will apply these techniques in a chip-based setup at Chalmers. A chip-based setup offers more intricate control; it will enable larger superposition states to be prepared (1pm), and allow quantum physics to be explored in a new parameter regime.