Questions tagged [time-crystals]
25 questions
33
votes
1 answer
Understanding time crystals
In very recent publications, two groups in Maryland (paper: "Observation of a Discrete Time Crystal") and Harvard (paper: "Observation of discrete time-crystalline order in a disordered dipolar many-body system") have separately worked on…
user929304
- 4,910
21
votes
2 answers
What could time crystals be useful for?
Time crystals have been theorized only a few years ago and confirmed recently. The articles reporting it don't talk about what they could be used for. Of course, every branch of physics can help us understand the world better, but have there been…
vsz
- 1,099
11
votes
1 answer
Time crystals: fake or revolution?
This article about time crystals just appeared on the PRL website.
Viewpoint: Crystals of Time (http://physics.aps.org/articles/v5/116)
The authors (including famous Frank Wilczek) claim that some systems in their ground state are time periodic and…
Sasha_F
- 371
11
votes
1 answer
What's the difference between a time crystal and a system undergoing periodic motion?
What's the difference between a time crystal and a system undergoing periodic motion? My understanding of a crystal is that it is a rigid body with a spatially periodic structure. Is any system undergoing periodic motion a time crystal, or is there…
Sean E. Lake
- 22,927
5
votes
0 answers
How can time crystals be useful in qRAM design?
A time crystal is a phase of a matter which is ordered in time, similar to classical crystals which are ordered spatially. In other words, the structure of a time crystal is ever-changing but with some period. In fact, time crystals are quantum…
Martin Vesely
- 1,125
3
votes
0 answers
What does breaking time translation symmetry mean? What's wrong with time crystal?
I was reading about a new state of matter which is called time crystal, this seemingly violates thermodynamic which had intrigue me. Someone told me that when you perform an experiment in the past, now or future the outcomes should be consistent…
user6760
- 13,214
3
votes
1 answer
Time Crystals - Question on the Hamiltonian for space crystals as in the seminal paper
I was going trough the paper "Classical Time Crystals" by A. Shapere and F. Wilczek, Physical Review Letters 109 (2012).
At the beginning they state that it is easy to construct Hamiltonians or Lagrangians whose lowest-energy state is a spatial…
Smerdjakov
- 547
3
votes
2 answers
Do time crystals require quantum entanglement?
In this video (at this time in the video) the vlogger seems to make a statement that the only way time crystals can be achieved is if some of the atoms (at a periodic distance from each other) are entangled. But I can't tell if I trust him…
Marc DiNino
- 875
3
votes
1 answer
What is internal space translation?
While I was reading the paper named "Classical time crystals," by A. Shapere and F. Wilczek, I found the following transformation.
$$f(x) \to f(x+e) - \frac{df}{dx}*e$$
It says the transformation is combined internal space-real space…
K.S. Kim
- 31
3
votes
0 answers
Can time crystals scatter incoming waves toward the past?
Can time crystals scatter incoming waves toward the past? I think it is a fair question to ask, albeit the answer is overwhelmingly likely NO. But since the concept is fairly new, I'm wondering if there could be on the horizon an experimental setup…
lurscher
- 14,933
2
votes
0 answers
Explicit time crystal in discrete spin chain
A time crystal is a system that exhibits time-periodic behavior in its ground state (GS) or in a nonequilibrium steady state, in the absence of an external periodic driving force. In particular for the GS, it exhibits time-periodic behavior, meaning…
Jahn Dorian
- 494
2
votes
0 answers
Time translational symmetry breaking
I have heard of time translational symmetry, which refers to the law of conservation of energy. Time crystals break time translational symmetry. I read on Wikipedia that it only breaks discrete-time translational symmetry and does not affect…
user_20411
- 171
2
votes
0 answers
Time Crystals: Rigidity, tuning of Hamiltonians
From my basic understanding of Time Crystals, we need a periodically driven Hamiltonian, say $H(t)$ with period $T$, $H(t)= H(T+t)$ and a local order parameter $O(t)$ with a period $nT$ satisfying rigidity and the periodic behavior should persist in…
esornep
- 41
2
votes
0 answers
What are the differences and similarities between Quantum synchronization and time-crystalisation?
I am learning about Quantum synchronization and read [1,2] on Sunday, which are about many-body bosonic systems. I understand that what happens when the system synchronizes is that all the particles in the system start oscillating in phase. In…
Steven Mathey
- 4,425
2
votes
1 answer
Why cant time-crystals form in thermal equilibrium?
This would make time-crystals a practically useless source of work, correct?
Sam B Tz
- 91