Effects of quantum fluctuations on macroscopic quantum tunneling and self-trapping of BEC in a double well trap

TL;DR

This paper investigates how quantum fluctuations, modeled by the Lee-Huang-Yang correction, affect macroscopic quantum tunneling and self-trapping in a two-component Bose-Einstein condensate within a double-well trap, combining analytical and numerical methods.

Contribution

It introduces a modified Gross-Pitaevskii model including quantum fluctuations and derives a dimer model to analyze tunneling and self-trapping phenomena.

Findings

Quantum fluctuations modify Josephson oscillation frequencies.

Conditions for self-trapping are analytically derived and confirmed numerically.

Quantum fluctuations influence tunneling and localization in BECs.

Abstract

We study the influence of quantum fluctuations on the macroscopic quantum tunneling and self-trapping of a two-component Bose-Einstein condensate in a double-well trap. Quantum fluctuations are described by the Lee-Huang-Yang term in the modified Gross-Pitaevskii equation. Employing the modified Gross-Pitaevskii equation in scalar approximation, we derive the dimer model using a two-mode approximation. The frequencies of Josephson oscillations and self-trapping conditions under quantum fluctuations are found analytically and proven by numerical simulations of the modified Gross-Pitaevskii equation. The tunneling and localization phenomena are investigated also for the case of the Lee-Huang-Yang fluid loaded in the double-well potential.