Comment on "Quantum Time Crystals and Interacting Gauge Theories in Atomic Bose-Einstein Condensates"
21 Apr 2020
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Syrwid Andrzej
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Kosior Arkadiusz
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Sacha Krzysztof
In a recent letter [Phys. Rev...Lett. 123, 250402], \"Ohberg and Wright
describe a Bose-Einstein condensate trapped on a ring in the presence of the
density-dependent gauge potential. It is claimed that the ground state of the
system corresponds to a rotating chiral bright soliton and consequently it
forms a genuine time crystal which minimizes its energy by performing periodic
motion. We show that the energy of the chiral soliton in the laboratory frame
is not correctly calculated in the letter. The correct energy becomes minimal
if the soliton does not move.(read more)