In Okinawa, a floating diamond the size of a fingernail just moved — pushed by nothing but the quantum spin of its own electrons

PhD student Anshuman Nayak and professor Jason Twamley's team at the Okinawa Institute of Science and Technology levitated a diamond laced with billions of nitrogen-vacancy centers — atomic defects that trap electrons like tiny quantum magnets — on a graphite plate floating above magnets. Then they pulsed it with a green laser, flipping the electrons' spins, and watched the whole 100-milligram assembly shift by about 100 nanometers. Published in Science Advances, it is the first time a quantum effect has nudged an object big enough for gravity to matter, pushing the quantum-classical boundary eight to nine orders of magnitude beyond anything before. The team sees a path to ultra-precise sensors for dark matter and gravitational waves — and, one day, a real-life test of Schrödinger's cat.