Superconducting microsphere levitated with magnetic trap.

Physicists in Sweden and Austria have used a magnetic trap to levitate a 48-μm-diameter sphere of superconducting material and keep it stable enough to characterise its motion, which could lead to a new generation of quantum sensors. The team constructed a chip-based magnetic trap from wires made of niobium, which becomes a superconductor at low temperatures. The levitation remained stable over a period of days, and the team says their experiment could make it possible to develop better sensors for force and acceleration, with applications in dark matter searches.