World’s fastest rotation at ETH

In their experiment, the research group at the ETH used a minuscule particle of glass with a diameter one thousand times smaller than a hair. They manipulated this in such a way as to make it turn around its own axis more than a billion times a second. “To do so, we trap the glass particle in a vacuum apparatus using so-called optical tweezers”, explained post-doc René Reimann in an ETH press release. Optical tweezers are created by a strongly focused laser beam, where the glass particle is levitated by light forces at the focus of the beam. This eliminates any direct mechanical contact with the outside world. In addition, air pressure in the apparatus is lower than normal, so single air molecules only very rarely collide with the particle.

The glass particles probably turned even more than a billion times per second, but researchers would need a faster photodetector than they currently have to measure any higher frequencies. Buying this detector is a top priority.

ETH reports in the press release that such measurements are important for nanotechnology, because they will offer new insights into the behaviour of materials under extreme stress.