Thursday, March 9, 2017

Scientists create a new form of matter - Time Crystals

Scientists create a new form of matter: Two studies show 'impossible' time crystals are real and could lead to quantum computer breakthrough


  • In time crystals, atoms follow a repeating pattern not in space, but in time
  • Made of interacting atoms that never ‘settle down’ to thermal equilibrium
  • Researchers say they could one day make for ultra-secure quantum computers 



Physicists have created a new form of matter in which atoms follow a repeating pattern not in space, but in time.

Dubbed ‘time crystals,’ these materials once thought to be impossible have now been successfully created in two separate studies, both of which were published this week in a peer-reviewed journal.

Physicists say these crystals ‘open the door to a whole new world of nonequilibrium phases,’ and could one day make for ultra-secure quantum computers.
Physicists have created a new form of matter in which atoms follow a repeating pattern not in space, but in time. Dubbed ‘time crystals,’ these materials once thought to be impossible have now been successfully created in two separate studies
Physicists have created a new form of matter in which atoms follow a repeating pattern not in space, but in time. Dubbed ‘time crystals,’ these materials once thought to be impossible have now been successfully created in two separate studies

TIME CRYSTALS 

While the atoms that make up crystals such as ice or diamond are arranged in a repeating pattern through space, the pattern behind time crystals repeats in time.
These strange crystals are made up of interacting atoms that never ‘settle down’ to thermal equilibrium.
Their structure repeats in time as they are ‘kicked’ periodically, similar to the way Jell-O jiggles when it is tapped. 
‘Wouldn’t it be super weird if you jiggled the Jell-O and found that somehow it responded at a different period?’ said Berkeley physicist Norman Yao.
‘But that is the essence of the time crystal. 
'You have some periodic driver that has a period ‘T,’ but the system somehow synchronizes so that you observe the system oscillating with a period that is larger than ‘T.’’ 
But, the researchers explain, repetition alone isn’t enough.
To hold it all together and make it 'rigid,' the crystal must have stable enough rhythm. 
While the atoms that make up crystals such as ice or diamond are arranged in a repeating pattern through space, the pattern behind time crystals repeats in time.

And, according to the researchers, their behaviour goes against the natural expectations.

In experiments at the University of Maryland-based Joint Quantum Institute (JQI), researchers teamed up with a group at the University of California, Berkeley to create time crystals by inducing three types of laser-driven behaviours in a chain of ten ytterbium ions.

They bombarded atomic ions with laser pulses to create a magnetic field, and used another laser to partially flip the spins of the atoms.

This sequence was repeated over and over, ultimately creating a pattern of flips that repeated in time.

And, the team found that the ions responded with a slower frequency – exactly half as fast as the pulses that drove them.

This bizarre response, they say, is like a hypothetical scenario in which a person hits a bunch of piano keys twice a second, but notes only come out once a second. 

A second group of researchers from Harvard University, also working with Berkeley physicist Norman Yao, created a time crystal using an artificial lattice in synthetic diamond.

Despite the different approaches, both efforts resulted in time crystalline behaviour.

Findings from both studies are being published this week in the journal Nature. 

The strange 'time crystals' are made up of interacting atoms that never ‘settle down’ to thermal equilibrium.

Their structure repeats in time as they are ‘kicked’ periodically, similar to the way Jell-O jiggles when it is tapped.
While the atoms that make up crystals such as ice or diamond are arranged in a repeating pattern through space, the pattern behind time crystals repeats in time. And, according to the researchers, their behaviour goes against the natural expectations
While the atoms that make up crystals such as ice or diamond are arranged in a repeating pattern through space, the pattern behind time crystals repeats in time. And, according to the researchers, their behaviour goes against the natural expectations

But, the researchers explain, repetition alone isn’t enough.

‘If you put a bunch of billiard balls on a pool table separated by exactly 10 centimeters, is that a crystal?’ says Jiehang Zhang, lead author and JQI/ UMD postdoctoral researcher.

‘Not really, because if you shake the table a little bit it will fall apart.’

To hold it all together and make it 'rigid,' the crystal must have stable enough rhythm.
In experiments at the University of Maryland-based Joint Quantum Institute (JQI), researchers teamed up with a group at the University of California, Berkeley to create time crystals by inducing three types of laser-driven behaviours in a chain of ten ytterbium ions
In experiments at the University of Maryland-based Joint Quantum Institute (JQI), researchers teamed up with a group at the University of California, Berkeley to create time crystals by inducing three types of laser-driven behaviours in a chain of ten ytterbium ions
The idea of a time crystal was first proposed in 2012 by physicist Frank Wilczek, who suggested a type of matter that can break translational symmetry in time.

With the recent breakthrough, physicists now say the new form of matter has implications for the future of quantum computing.
‘This bizarre state of matter results from a complex interplay between many quantum controls at the individual atomic level,’ says Christopher Monroe, a UMD Distinguished University Professor of Physics and a JQI Fellow.

‘But time crystals can also emerge in certain solid-state device, so a general understanding of this phenomenon could help bring such systems into future quantum devices.’


Read more: http://www.dailymail.co.uk/sciencetech/article-4295370/Two-studies-impossible-time-crystals-real.html#ixzz4aswGT6u9
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