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From New Scientist
Ordinary crystals are three-dimensional objects whose atoms are arranged in regular, repeating patterns – just like table salt. They adopt this structure because it uses the lowest amount of energy possible to maintain.
Earlier this year, Frank Wilczek, a theoretical physicist at the Massachusetts Institute of Technology, speculated that a similar structure might repeat regularly in the fourth dimension – time.
Wilczek has also theorised that a working time crystal could be made into a computer, with different rotational states standing in for the 0s and 1s of a conventional computer.
The article includes a description (by Tongcang Li from the University of California, and others) of how such a time crystal could be built. Though it will be tricky because building the crystal will need temperatures close to absolute zero.
While Wilczek points out that the heat-death of the universe is, in principle, "very user friendly" for this kind of experiment because it would be cold and dark, there are other issues to consider.
Original Submission
(Score: 4, Interesting) by cosurgi on Monday July 06 2015, @07:37PM
I'm reading the full paper now, you can enjoy it too since library genesis isn't closed yet [soylentnews.org]. Just go there, click "Scientific articles" and search for "Quantum time crystals". I won't post the link here to avoid making troubles for our site. You have to figure it out yourself.
The paper is very interesting. Though not completely clear.
1. I am not sure how to understand "multivalued" in 2nd paragraph on 2nd page: "since fi, acting on wave functions in Hilbert space, is multivalued". I know what "multivalued" means, I have just never encountered such a beast (as Wilczek calls it "non-legitimate operator") in QM.
2. I am not sure if delta in Eq.13 is a Dirac's delta or just a symbol for the potential. (I assume it's Dirac's delta).
Apart from that I see that comprehending this paper a bit more would take me about two weeks :) Too bad I'm in hurry now, but hopefully will get back to it later.
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(Score: 4, Informative) by boristhespider on Monday July 06 2015, @08:23PM
Nothing dubious needed. It's worth noting that the NS article is from 2012, so the "earlier this year" is a bit misleading from a 2015 perspective.
http://arxiv.org/abs/1202.2537 [arxiv.org] "Classical Time Crystals", Shapere and Wilczek
http://arxiv.org/abs/1202.2539, [arxiv.org] "Quantum Time Crystals", Wilczek (the paper you're referring to)
http://arxiv.org/abs/1206.4772, [arxiv.org] "Space-time crystals of trapped ions", Li et al (the other paper referred to in the article)
(Score: 2) by cosurgi on Monday July 06 2015, @09:04PM
Thanks!
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(Score: 0) by Anonymous Coward on Monday July 06 2015, @09:53PM
No problem. Also that's definitely a Dirac delta in the potential. I only skimmed it but from what he said about phidot, I'd suspect that phi is "multivalued" in the sense that it has multiple branches. But as I say I'd have to read it and quantum mechanics (or field theory, come to that) is very far from my field.
(Score: 2) by boristhespider on Monday July 06 2015, @09:54PM
Sorry, that was me. Posted via my work machine which I don't use logins (other than email) on.
(Score: 4, Insightful) by frojack on Monday July 06 2015, @10:42PM
I'm reading the full paper now, you can enjoy it too since library genesis isn't closed yet [soylentnews.org]. Just go there, click "Scientific articles" and search for "Quantum time crystals". I won't post the link here to avoid making troubles for our site. You have to figure it out yourself.
Translation: I'm too lazy to post a link of the page I have up in my other browser window.
No, you are mistaken. I've always had this sig.
(Score: 2) by cosurgi on Tuesday July 07 2015, @10:54AM
Not really, maybe I'm weird, but I was trying to play it safe :)
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#\ @ ? [adom.de] Colonize Mars [kozicki.pl]
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