Quantum gas goes below absolute zero

@article{Merali2013QuantumGG,
  title={Quantum gas goes below absolute zero},
  author={Zeeya Merali},
  journal={Nature},
  year={2013}
}
Ultracold atoms pave way for negative-Kelvin materials. 
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References

SHOWING 1-4 OF 4 REFERENCES
Equilibration rates and negative absolute temperatures for ultracold atoms in optical lattices.
TLDR
It is shown theoretically that, by reversing the confining potential, stable superfluid condensates at finite momentum and T<0 can be created with low entropy production for attractive bosons. Expand
Spin gradient demagnetization cooling of ultracold atoms.
We demonstrate a new cooling method in which a time-varying magnetic field gradient is applied to an ultracold spin mixture. This enables preparation of isolated spin distributions at positive and… Expand
Negative Absolute Temperature for Motional Degrees of Freedom
TLDR
An attractively interacting ensemble of ultracold bosons at negative temperature that is stable against collapse for arbitrary atom numbers is created by tailoring the Bose-Hubbard Hamiltonian, enabling fundamentally new many-body states. Expand
Interacting fermionic atoms in optical lattices diffuse symmetrically upwards and downwards in a gravitational potential.
TLDR
A cloud of fermionic atoms in an optical lattice described by a Hubbard model with an additional linear potential is considered, showing that the width of the cloud increases with t^{1/3} for long times consistent with results from the Boltzmann simulations. Expand