First observation of quantum spins shifting a centimeter-scale object in the lab

Researchers from the Okinawa Institute of Science and Technology (OIST) have for the first time observed quantum spin forces manipulating a centimeter-sized object under the influence of gravity. This breakthrough, published in Science Advances, pushes the boundaries of our understanding between quantum and classical physics.

Large objects are inherently challenging to isolate from environmental factors like heat and vibration, making it difficult to observe quantum phenomena that typically affect subatomic particles. However, the OIST team demonstrated that quantum effects can be harnessed to move a levitating, centimeter-wide diamond with the force generated solely by electron spin.

Professor Jason Twamley explains that this achievement represents a significant step forward in testing the quantum nature of gravity. By levitating macroscale objects using diamagnetic techniques, the researchers were able to overcome the challenges posed by environmental noise. They achieved this by combining a diamagnetically levitated graphite plate with a diamond, which contains billions of nitrogen-vacancy (NV) centers acting as tiny, controllable quantum magnets.

The NV diamonds were polarized using a green laser, creating magnetic fluctuations that pushed the diamond down. The motion of the diamond was tracked with high precision using an interferometer, measuring distance changes at the picometer level.

This groundbreaking experiment opens up new avenues for exploring the fundamental nature of our universe and developing highly accurate sensors for detecting exotic phenomena such as dark matter and gravitational waves. By demonstrating a mechanical effect arising solely from quantum spin, the OIST team has created an experimental platform to test theories that bridge the gap between quantum and classical physics.