May 6, 2021
Two new papers published on Thursday in Science push the boundaries of the quantum effects physicists can achieve at a macroscopic scale. Both studies observed such effects in thin aluminum “drums” about the size of a red blood cell. In the first study, U.S. and Israeli researchers directly and reliably measured quantum entanglement between the drums. And the second study, led by a Finnish team, measured entangled drums while avoiding “back action,” the inevitable noise associated with the very act of trying to measure an object’s position and momentum.
In the classical world, there is no theoretical limit to the precision of such measurements. But the uncertainty principle, formulated by German physicist Werner Heisenberg in the 1920s, states that there is a fundamental limit to how well the position and momentum of an object such as a drum can be known. “The tricks described in these two papers are ways of evading what you might have thought is the limit on measuring forces coming from the Heisenberg uncertainty principle,” says Aashish Clerk, a condensed matter physicist at the University of Chicago, who was not involved with either study.