Quantum spins move a visible object: laser nudges a diamond in Okinawa
OIST researchers show quantum effects in a diamond can move a roughly centimeter-sized object, a step toward ultra-precise sensors.
Photo: OIST from Onna Village, Japan / Wikimedia Commons, CC BY 2.0 (cropped and resized)
Researchers at the Okinawa Institute of Science and Technology in Japan have shown that quantum effects can move an object about one centimeter in size and weighing 100 milligrams. That is 100 million to 1 billion times heavier than objects used in earlier comparable experiments. The study was published in the journal Science Advances.
The team suspended a diamond containing billions of nitrogen-vacancy centers, defects in the crystal lattice that carry a quantum spin, from a carbon rod connected to a magnetically levitated graphite plate. Pulses from a 50-milliwatt green laser set the spins and create a tiny downward force that moves the diamond. An interferometer tracks the motion with picometer precision. “We've shown a large classical response from a small quantum effect,” said Professor Jason Twamley.
The practical aim is highly precise sensors that could help in the search for dark matter and gravitational waves. In the long run, the researchers want to put a massive object into a quantum superposition to test whether gravity follows quantum rules, something so far achieved only with microscopic systems. “All we need is another order of magnitude,” Twamley said.