Researchers at Aalto University\u2019s Department of Applied Physics have, for the first time, connected time crystals to another system external to itself.<\/p>\n
The study describes how the team turned a time crystal into an optomechanical system that could be used to develop things like extremely accurate sensors or memory systems<\/a> for quantum computers, significantly boosting their power.<\/p>\n Jere M\u00e4kinen, who led the study, explained: \u201cPerpetual motion is possible in the quantum realm so long as it is not disturbed by external energy input, such as by observing it.<\/p>\n \u201cThat is why time crystals had never before been connected to any external system. However, we did just that and showed, also for the first time, that you can adjust the crystal\u2019s properties using this method.\u201d<\/p>\n A brief history of time crystals<\/p>\n A glittering hunk of crystal gets its iridescence from a highly regular atomic structure.\u00a0 Frank Wilczek, the 2012 Nobel Laureate in Physics, proposed that quantum systems could construct themselves in the same way, but in time instead of space.<\/p>\n He dubbed such systems time crystals, defining them by their lowest possible energy state, which perpetually repeats movements without external energy input.<\/p>\n Therefore, these crystals were experimentally proved to exist in 2016.<\/p>\n Observing changes in the frequency of time crystals<\/p>\n The researchers used radio waves to pump magnons into a Helium-3 superfluid cooled to near-absolute zero.<\/p>\n When the team turned off the pump, the magnons formed a time crystal that stayed in motion for an unprecedentedly long time, lasting up to 108 cycles or several minutes before fading down to a level the researchers could no longer observe.<\/p>\n During the fading process, the crystal connected itself to a nearby mechanical oscillator in a way determined by the oscillator\u2019s frequency and amplitude.<\/p>\n \u201cWe showed that changes in the time crystal\u2019s frequency are completely analogous to optomechanical phenomena widely known in physics,\u201d M\u00e4kinen stated.<\/p>\n \u201cThese are the same phenomena that are used, for example, in detecting gravitational waves<\/a> at the Laser Interferometer Gravitational-Wave Observatory in the US.<\/p>\n \u201cBy reducing the energy loss and increasing the frequency of that mechanical oscillator, our setup could be optimised to reach down near the border of the quantum realm.\u201d<\/p>\n Implications for quantum computing<\/p>\n