Impact of the transverse direction on the many-body tunneling dynamics in a two-dimensional bosonic Josephson junction

TL;DR

This paper theoretically investigates how the transverse direction influences many-body tunneling dynamics of bosonic clouds in a 2D double-well potential, revealing that transverse excitations accelerate decoherence during tunneling.

Contribution

It introduces a detailed analysis of transverse effects on tunneling in a 2D bosonic system using MCTDHB, highlighting the impact of transverse excitations on coherence loss.

Findings

Transverse excitations speed up decoherence during tunneling.

States with transverse excitations lose coherence faster.

Tunneling dynamics depend on initial state configurations.

Abstract

Tunneling in a many-body system appears as one of the novel implications of quantum physics, in which particles move in space under an otherwise classically-forbidden potential barrier. Here, we theoretically describe the quantum dynamics of the tunneling phenomenon of a few intricate bosonic clouds in a closed system of a two-dimensional symmetric double-well potential. We examine how the inclusion of the transverse direction, orthogonal to the junction of the double-well, can intervene in the tunneling dynamics of bosonic clouds. We use a well-known many-body numerical method, called the multiconfigurational time-dependent Hartree for bosons (MCTDHB) method. MCTDHB allows one to obtain accurately the time-dependent many-particle wavefunction of the bosons which in principle entails all the information of interest about the system under investigation. We analyze the tunneling dynamics by preparing the initial state of the bosonic clouds in the left well of the double-well either as the ground, longitudinally or transversely excited, or a vortex state. We unravel the detailed mechanism of the tunneling process by analyzing the evolution in time of the survival probability, depletion and fragmentation, and the many-particle position, momentum, and angular-momentum expectation values and their variances. As a general rule, all objects lose coherence while tunneling through the barrier and the states which include transverse excitations do so faster. Implications are briefly discussed.