TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.12.3.092
TI  - The origin of the period-$2T/7$ quasi-breathing in disk-shaped Gross-Pitaevskii breathers
PY  - 2022/03/14
UR  - https://scipost.org/SciPostPhys.12.3.092
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 12
IS  - 3
SP  - 092
A1  - Torrents, Jordi
AU  - Dunjko, Vanja
AU  - Gonchenko, Marina
AU  - Astrakharchik, Grigori E.
AU  - Olshanii, Maxim
AB  - We address the origins of the quasi-periodic breathing observed in [Phys. Rev.\ X vol. 9, 021035 (2019)] in disk-shaped harmonically trapped two-dimensional Bose condensates, where the quasi-period $T_{\text{quasi-breathing}}\sim$~$2T/7$ and $T$ is the period of the harmonic trap. We show that, due to an unexplained coincidence, the first instance of the collapse of the hydrodynamic description, at $t^{*} = \arctan(\sqrt{2})/(2\pi) T \approx T/7$, emerges as a `skillful impostor' of the quasi-breathing half-period $T_{\text{quasi-breathing}}/2$. At the time $t^{*}$, the velocity field almost vanishes, supporting the requisite time-reversal invariance. We find that this phenomenon persists for scale-invariant gases in all spatial dimensions, being exact in one dimension and, likely, approximate in all others. In $\bm{d}$ dimensions, the quasi-breathing half-period assumes the form $T_{\text{quasi-breathing}}/2 \equiv t^{*} = \arctan(\sqrt{d})/(2\pi) T$. Remaining unresolved is the origin of the period-$2T$ breathing, reported in the same experiment.
ER  -

@Article{10.21468/SciPostPhys.12.3.092,
	title={{The origin of the period-$2T/7$ quasi-breathing in disk-shaped Gross-Pitaevskii breathers}},
	author={Jordi Torrents and Vanja Dunjko and Marina Gonchenko and Gregory E. Astrakharchik and Maxim Olshanii},
	journal={SciPost Phys.},
	volume={12},
	pages={092},
	year={2022},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.12.3.092},
	url={https://scipost.org/10.21468/SciPostPhys.12.3.092},
}