# Time Crystals in Ultracold Matter

@article{Mendona2014TimeCI, title={Time Crystals in Ultracold Matter}, author={Jos{\'e} Tito Mendonça and Viktor V. Dodonov}, journal={Journal of Russian Laser Research}, year={2014}, volume={35}, pages={93-100} }

We consider the formation of time crystals in a gas of laser-cooled atoms. We show that the phonon frequency is shifted inside a time crystal, and the phonon backscattering resulting from a temporal Bragg diffraction can be observed. A quantum-field description allows us to demonstrate that these effects are accompanied by emission of the phonon pairs from vacuum. The same description can be used for the dynamical Casimir effect, which, in some sense, is as a special case of the time crystal…

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## References

SHOWING 1-10 OF 36 REFERENCES

Collective oscillations of ultracold matter

- Physics
- 2010

We consider the collective oscillations of an ultracold atomic cloud by using a wave kinetic description which retains phonon recoil effects. We derive an exact quantum-wave dispersion relation for…

Optical properties of atomic Mott insulators: From slow light to dynamical Casimir effects

- Physics
- 2008

We theoretically study the optical properties of a gas of ultracold, coherently dressed three-level atoms in a Mott insulator phase of an optical lattice. The vacuum state, the band dispersion and…

Collective oscillations in ultracold atomic gas

- Physics
- 2008

Using both fluid and kinetic descriptions, where repulsive forces between near by atoms are included, we discuss the basic oscillations and waves of a cloud of ultra-cold atoms confined in a…

Space-time crystals of trapped ions.

- Materials Science, MedicinePhysical review letters
- 2012

The proposed space-time crystals of trapped ions provide a new dimension for exploring many-body physics and emerging properties of matter and are robust for direct experimental observation.

Density correlations and analog dynamical Casimir emission of Bogoliubov phonons in modulated atomic Bose-Einstein condensates

- Physics
- 2009

AbstractWe present a theory of the density correlations that appear in an atomic Bose-Einstein condensate as a consequence of the emission of correlated pairs of Bogoliubov phonons by a…

Vacuum effects in a vibrating cavity: Time refraction, dynamical Casimir effect, and effective Unruh acceleration

- Physics
- 2008

Two different quantum processes are considered in a perturbed vacuum cavity: time refraction and dynamical Casimir effect. They are shown to be physically equivalent, and are predicted to be…

Time refraction and the quantum properties of vacuum (8 pages)

- Physics
- 2005

We present the classical and quantum theory of time refraction in a generic nonstationary medium. The classical approach leads to expressions for the temporal refraction coefficient, and the temporal…

Probing quantum-vacuum geometrical effects with cold atoms.

- Physics, MedicinePhysical review letters
- 2008

The theoretical expression of the lateral Casimir-Polder force between an atom and a corrugated surface is derived in the scattering approach and it is shown that large corrections to the "proximity force approximation" could be measured using present-day technology with a Bose-Einstein condensate used as a vacuum field sensor.

Nonlinear coherent modes of trapped Bose-Einstein condensates

- Physics
- 2002

Nonlinear coherent modes are the collective states of trapped Bose atoms, corresponding to different energy levels. These modes can be created starting from the ground-state condensate that can be…

Detection scheme for acoustic quantum radiation in Bose-Einstein condensates.

- Physics, MedicinePhysical review letters
- 2006

A detection scheme for sound waves in dilute Bose-Einstein condensates is proposed whose accuracy might reach down to the level of a few or even single phonons, which could open up a new range of applications including the experimental observation of quantum radiation phenomena.