Ultracold Big Bang experiment successfully simulates evolution of early universe | UChicago News: These excitations are called Sakharov acoustic oscillations, named for Russian physicist Andrei Sakharov, who described the phenomenon in the 1960s. To produce Sakharov oscillations, Chin’s team chilled a flat, smooth cloud of 10,000 or so cesium atoms to a billionth of a degree above absolute zero, creating an exotic state of matter known as a two-dimensional atomic superfluid.
Then they initiated a quenching process that controlled the strength of the interaction between the atoms of the cloud. They found that by suddenly making the interactions weaker or stronger, they could generate Sakharov oscillations.
The universe simulated in Chin’s laboratory measured no more than 70 microns in diameter, approximately the diameter as a human hair.