Fabian Resare, Kvantteknologi

Sammanfattning:

While quantum mechanics is well known for yielding precise predictions of microscopic physics experiments, the absence of quantum phenomena like superposition at macroscopic scales posits the question: Is there something fundamental preventing this from happening?

I will present progress on chip-based magnetic levitation of superconducting microparticles, one of several promising experimental approaches to study this question as well as to explore
quantum-enhanced sensing, for example applicable in searches for exotic particles. I will specifically present results on deterministic loading of microparticles into a chip-based magnetic trap by developing
surface treatments that reduce the adhesion between the substrate and microparticle. To this end, the adhesion force for different surfaces was measured and a statistical model was used to predict particle detachment. I have found simple surface treatments that can decrease the
force required to detach 50% of particles by a factor of six, enabling reliable levitation.

Ultimately, a realistic quantum protocol is required to generate a superposition state of the microparticle. I will present a novel protocol that exploits higher-order magnetic traps, capable of generating a double-well potential purely from magnetic fields. By numerical simulations of the phase space dynamics, I have confirmed the capability of these potentials to generate negativity in the Wigner quasiprobability distribution of the particle’s motion.

Overall, my results form contributions to future quantum magnetomechanics experiments with micron-scale particles.