Physicists have cooled a nanoparticle to the lowest temperature quantum mechanics allows by reducing its motion to the ground state.
This, they say, may allow for otherwise unachievable quantum manipulations of objects involving large masses – and offers a new platform for studying macro-quantum physics more broadly.
While the particle they manipulated was small, it was millions of times larger and far more complex than the atomic-scale objects most often used to investigate quantum motion.
Writing in the journal Science, Uroš Delić from the University of Vienna and colleagues say this was all made possible by the recent breakthrough application of coherent scattering in the field of cavity optomechanics.
Using lasers to optically levitate, ensnare and cool atoms has enabled the isolation and study of the quantum properties of individual atoms and quantum gasses. Delić’s team applied these techniques to trap and suspend a solid-state 150-nanometre glass sphere containing 100 million atoms.
Starting from room temperature, they laser-cooled the nanoparticle to its ground state – a temperature of roughly minus 273 degrees Celsius.