Google says it has created a time crystal in a quantum computer, and it's weirder than you can imagine
In what could be the first useful application of quantum computing, Google's scientists have demonstrated the existence of a new phase of matter.



https://www.youtube.com/watch?v=ucwmGZ51X7E



In a new research paper, Google scientists claim to have used a quantum processor for a useful scientific application: to observe a genuine time crystal.

If 'time crystal' sounds pretty sci-fi that's because they are. Time crystals are no less than a new "phase of matter", as researchers put it, which has been theorized for some years now as a new state that could potentially join the ranks of solids, liquids, gases, crystals and so on. The paper remains in pre-print and still requires peer review.

Time crystals are also hard to find. But Google's scientists now rather excitingly say that their results establish a "scalable approach" to study time crystals on current quantum processors.

Understanding why time crystals are interesting requires a little bit of background in physics – particularly, knowledge of the second law of thermodynamics, which states that systems naturally tend to settle in a state known as "maximum entropy".

To take an example: if you pour some milk into a coffee cup, the milk will eventually dissolve throughout the coffee, instead of sitting on the top, enabling the overall system to come to an equilibrium. This is because there are many more ways for the coffee to randomly spread throughout the coffee than there are for it to sit, in a more orderly fashion, at the top of the cup.

This irresistible drive towards thermal equilibrium, as described in the second law of thermodynamics, is reflective of the fact that all things tend to move towards less useful, random states. As time goes on, systems inevitably degenerate into chaos and disorder – that is, entropy

Time crystals, on the other hand, fail to settle in thermal equilibrium. Instead of slowly degenerating towards randomness, they get stuck in two high-energy configurations that they switch between – and this back-and-forth process can go on forever.

To explain this better, Curt von Keyserlingk, lecturer at the school of physics and astronomy at the University of Birmingham, who did not participate in Google's latest experiment, pulls out some slides from an introductory talk to prospective undergraduate students. "They usually pretend to understand, so it might be useful," von Keyserlingk warns ZDNet.

It starts with a thought experiment: take a box in a closed system that is isolated from the rest of the universe, load it with a couple of dozens of coins and shake it a million times. As the coins flip, tumble and bounce off each other, they randomly move positions and increasingly become more chaotic. Upon opening the box, the expectation is that you will be faced with roughly half the coins on their heads side, and half on their tails.

It doesn't matter if the experiment started with more coins on their tails or more coins on their heads: the system forgets what the initial configuration was, and it becomes increasingly random and chaotic as it is shaken.

This closed system, when it is translated into the quantum domain, is the perfect setting to try and find time crystals, and the only one known to date. "The only stable time crystals that we've envisioned in closed systems are quantum mechanical," says von Keyserlingk.

Read the rest here:
https://www.zdnet.com/article/google-says-it-has-created-a-time-crystal-in-a-quantum-computer-and-its-weirder-than-you-can-imagine/




https://www.youtube.com/watch?v=LGWi50JPbmE