That tiny speck in the middle of the picture above is a glass nanosphere measuring 100 nanometer across (about 100 smaller than the width of a human hair).
It's pretty small, but relatively large when compared to atomic-level stuff that scientists used to work with. Over time, physicists have continued to put ever larger objects at their quantum limit by cooling them down to near absolute zero.
Now, researchers at ETH Zurich have managed to trap the tiny glass nanosphere using laser and slowed its thermal motion to the lowest quantum mechanical state.
From ETH Zurich:
The macroscopic object in [professor Lukas Novotny’s] laboratory is a tiny sphere made of glass. Although it is only a hundred nanometres in diameter, it consists of as many as ten million atoms. Using a tightly focused laser beam, the sphere is made to hover in an optical trap inside a vacuum container cooled down to 269 degrees below zero. The lower the temperature, the smaller is the thermal motion. “However, to clearly see quantum effects the nanosphere needs to be slowed down even more, all the way to its motional ground state”, explains Felix Tebbenjohanns, a postdoc in Novotny’s lab. The oscillations of the sphere, and hence its motional energy, are reduced to the point where the quantum mechanical uncertainty relation forbids a further reduction. “This means that we freeze the motional energy of the sphere to a minimum that is close to the quantum mechanical zero-point motion”, Tebbenjohanns says.
While much of the scientific findings are academic, this achievement may one day help in creating a much more sensitive sensor technology.
#quantumphysics #laser #nanosphere #glass
Image: ETH Zurich