Credit: Chris Monroe, University of Maryland
source : university of California – Berkeley.
scientists are really thrilling the world with new discoveries everyday and the newest discovery is that of a new state of matter called the time crystal.
Normal crystals, likes
diamond, are an
atomic lattice that repeats in space, but
physicists recently suggested making
materials that repeat in time. Last year,
reseachers sketched out the phases
surrounding a time crystal and what to
measure in order to confirm that this new
material is actually a stable phase of
matter. This stimulated two teams to build a
time crystal, the first examples of a non-
equilibrium form of matter.
To Norman Yao, these inert crystals are the
tip of the iceberg.
If crystals have an atomic structure that
repeats in space, like the carbon lattice of a
diamond, why can’t crystals also have a
structure that repeats in time? That is, a time
In a paper published online last week in the
journal Physical Review Letters, the University
of California, Berkeley assistant professor of
physics describes exactly how to make and
measure the properties of such a crystal, and
even predicts what the various phases
surrounding the time crystal should be — akin
to the liquid and gas phases of ice.
This is not mere speculation. Two groups
followed Yao’s blueprint and have already
created the first-ever time crystals. The groups
at the University of Maryland and Harvard
University reported their successes, using two
totally different setups, in papers posted
online last year, and have submitted the
results for publication. Yao is a co-author on
Time crystals repeat in time because they are
kicked periodically, sort of like tapping Jell-O
repeatedly to get it to jiggle, Yao said. The big
breakthrough, he argues, is less that these
particular crystals repeat in time than that
they are the first of a large class of new
materials that are intrinsically out of
equilibrium, unable to settle down to the
motionless equilibrium of, for example, a
diamond or ruby.
“This is a new phase of matter, period, but it
is also really cool because it is one of the first
examples of non-equilibrium matter,” Yao
said. “For the last half-century, we have been
exploring equilibrium matter, like metals and
insulators. We are just now starting to explore
a whole new landscape of non-equilibrium
While Yao is hard put to imagine a use for a
time crystal, other proposed phases of non-
equilibrium matter theoretically hold promise
as nearly perfect memories and may be useful
in quantum computers.
The Harvard team, led by Mikhail Lukin, set up
its time crystal using densely packed nitrogen
vacancy centers in diamonds.
1. N. Y. Yao, A. C. Potter, I.-D. Potirniche,
A. Vishwanath. Discrete Time Crystals:
Rigidity, Criticality, and Realizations.
Physical Review Letters, 2017; 118 (3)