Entanglement of an array of massive, magnetically levitated superconducting microparticles on a chip (SuperQLev)

Research Project, 2024 – 2028

Quantum states of massive objects have fascinated us since the inception of quantum mechanics. Nowadays molecules of thousands of atoms and nanomechanical resonators weighing picogram can be brought into quantum states. This capability enables tests of the validity of quantum mechanics and provides new avenues for quantum technologies. Entangled states are particularly relevant in this context as they unlock multipartite quantum correlations that, amongst others, enable precise measurements beyond the standard quantum limit and novel tests for the interplay between quantum mechanics and gravity. However, no experiment to date demonstrated entanglement between a scalable number of massive particles, which would access a novel parameter regime in terms of mass, quantum correlation, and particle number. SuperQLev will fill this gap and demonstrate entanglement of the center-of-mass motion of an array of magnetically levitated superconducting microparticles on chip. This achievement will break new ground by exploring multipartite quantum states of massive objects ranging over six orders of magnitude in mass, from pico- to microgram. SuperQLev will make this possible by merging two technologies into a unique experimental platform. The first technology is magnetic levitation of superconducting microparticles, which offers the capability of levitating massive particles at ultralow mechanical dissipation. My group has made pioneering contributions by realizing chip-based magnetic levitation of superconducting microparticles. The second technology is superconducting quantum circuits that offer a versatile toolbox for quantum control. SuperQLev will merge these two platforms to reach quantum control over the motion of levitated superconducting particles via inductive coupling to superconducting circuits. This hitherto unexplored hybrid quantum platform allows SuperQLev to conduct ground-breaking proof-of-principle experiments in quantum sensing and fundamental physics.