As the story goes, the Greek mathematician and tinkerer Archimedes came across an invention while traveling through ancient Egypt that would later bear his name. It was a machine consisting of a screw housed inside a hollow tube that trapped and drew water upon rotation. Now, researchers led by Stanford University physicist Benjamin Lev have developed a quantum version of Archimedes’ screw that, instead of water, hauls fragile collections of gas atoms to higher and higher energy states without collapsing. Their discovery is detailed in a paper published Jan. 14 in Science.
“My expectation for our system was that the stability of the gas would only shift a little,” said Lev, who is an associate professor of applied physics and of physics in the School of Humanities and Sciences at Stanford. “I did not expect that I would see a dramatic, complete stabilization of it. That was beyond my wildest conception.”
Along the way, the researchers also observed the development of scar states—extremely rare trajectories of particles in an otherwise chaotic quantum system in which the particles repeatedly retrace their steps like tracks overlapping in the woods. Scar states are of particular interest because they may offer a protected refuge for information encoded in a quantum system. The existence of scar states within a quantum system with many interacting particles—known as a quantum many-body system—has only recently been confirmed. The Stanford experiment is the first example of the scar state in a many-body quantum gas and only the second ever real-world sighting of the phenomenon.