27
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Understanding time crystals
The key idea is that time crystals are externally driven at a certain frequency, but they respond at a different (in fact, slower) frequency.
First of all, terminology:
what does it have in common ...
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13
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What could time crystals be useful for?
This is a review article on the status of the research by summer of 2017. I copy the conclusions:
In the present article we have reviewed current state of
the art of investigations of time ...
- 220k
11
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What's the difference between a time crystal and a system undergoing periodic motion?
A crystal is a system which spontaneously breaks the translation symmetry of the underlying physical laws.
Similarly, a time crystal is a system which is subject to a periodic driving with period $T$,...
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2
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Time crystals: fake or revolution?
A flaw in Wilczek's argument has been pointed out in PRL 110, 118901 (2013). In short, the rotating soliton exhibited by Wilczek is not the correct ground state of the system. The true ground state ...
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2
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Time Crystals - Question on the Hamiltonian for space crystals as in the seminal paper
In the first example with potential $V_1(\phi)$, the symmetry being broken is the spatial translation symmetry, $x \rightarrow x + a$. The potential doesn't change under this transformation, but since ...
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Do time crystals require quantum entanglement?
It depends entirely on your exact definitions. Many times, someone has proposed a "classical time crystal", but then someone else has argued that that isn't a "true" time crystal because it's time ...
- 41.3k
1
vote
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Quantum Time Crystals
He is referring to a more precise definition of order parameter. The idea is to capture spontaneous symmetry breaking: the ground states of the system are not individually invariant under the ...
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What does it mean to be less symmetrical than the equations governing the system?
An example would a Lennard Jones crystal. In two dimensions, at low enough temperature, it forms a hexagonal phase
Yet in the Hamiltonian there is nothing that hints at 6-fold symmetry at all. The ...
1
vote
Accepted
Do time crystals require quantum entanglement?
A quantum time crystal does not from my reading of Wilczek and others appear to require entanglement, but the idea is interesting. It does seems plausible that a quantum time crystal model could be ...
- 12.3k
1
vote
Accepted
Trying to understand crystal structures within a solid
Let me try to explain with an example. Let's consider for instance the honeycomb lattice shown below. What type of lattice is this? Now since this is a two dimensional structure, we might expect that ...
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Why cant time-crystals form in thermal equilibrium?
If you consult the September, 2018, issue of Physics Today you will find an excellent article on time crystals by N Yao and C Nayak (p 41). Paraphrasing their synopsis, time crystals result when the ...
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Could spacetime have crystalline properties?
I am going to make this brief. As pointed out space has a crystalline structure in LQG. This has some odd problems in that it violates Lorentz invariance on scales close to the scale length of the ...
- 12.3k
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