Scientists have created the first "time-crystal" two-body system in an
experiment that seems to bend the laws of physics.
It comes after the same team recently witnessed the first interaction of the
new phase of matter.
Time crystals were long believed to be impossible because they are made from
atoms in never-ending motion. The discovery, published in Nature
Communications, shows that not only can time crystals be created, but they
have potential to be turned into useful devices.
Time crystals are different from a standard crystal—like metals or
rocks—which is composed of atoms arranged in a regularly repeating pattern
in space.
First theorized in 2012 by Nobel Laureate Frank Wilczek and identified in
2016, time crystals exhibit the bizarre property of being in constant,
repeating motion in time despite no external input. Their atoms are
constantly oscillating, spinning, or moving first in one direction, and then
the other.
EPSRC Fellow Dr. Samuli Autti, lead author from Lancaster University's
Department of Physics, explained: "Everybody knows that perpetual motion
machines are impossible. However, in quantum physics perpetual motion is
okay as long as we keep our eyes closed. By sneaking through this crack we
can make time crystals."
"It turns out putting two of them together works beautifully, even if time
crystals should not exist in the first place. And we already know they also
exist at room temperature."
A "two-level system" is a basic building block of a quantum computer. Time
crystals could be used to build quantum devices that work at room
temperature.
An international team of researchers from Lancaster University, Royal
Holloway London, Landau Institute, and Aalto University in Helsinki observed
time crystals by using Helium-3 which is a rare isotope of helium with one
missing neutron. The experiment was carried out in Aalto University.
They cooled superfluid helium-3 to about one ten thousandth of a degree from
absolute zero (0.0001 K or -273.15 C). The researchers created two time
crystals inside the superfluid, and brought them to touch. The scientists
then watched the two time crystals interacting as described by quantum
physics.
Reference:
Nonlinear two-level dynamics of quantum time crystals, Nature Communications
(2022).
DOI: 10.1038/s41467-022-30783-w
Tags:
Physics