New Journal of Physics (Jan 2024)

Quantum fluctuations in atomic Josephson junctions: the role of dimensionality

  • A Bardin,
  • F Lorenzi,
  • L Salasnich

DOI
https://doi.org/10.1088/1367-2630/ad127b
Journal volume & issue
Vol. 26, no. 1
p. 013021

Abstract

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We investigate the role of quantum fluctuations in the dynamics of a bosonic Josephson junction in D spatial dimensions, by using beyond-mean-field Gaussian corrections. We derive some key dynamical properties in a systematic way for $D = 3, 2, 1$ . In particular, we compute the Josephson frequency in the regime of low population imbalance. We also obtain the critical strength of the macroscopic quantum self-trapping. Our results show that quantum corrections increase the Josephson frequency in spatial dimensions D = 2 and D = 3, but they decrease it in the D = 1 case. The critical strength of macroscopic quantum self-trapping is instead reduced by quantum fluctuations in D = 2 and D = 3 cases, while it is enhanced in the D = 1 configuration. We show that the difference between the cases of D = 2 and D = 3 on one side, and D = 1 on the other, can be related to the qualitatively different dependence of the interaction strength on the scattering length in the different dimensions.

Keywords