Josephson oscillation in the dissipative Bose-Hubbard dimer

TL;DR

This paper investigates Josephson oscillations in an open, dissipative Bose-Hubbard dimer, demonstrating how external driving initiates oscillations and analyzing the decay caused by dephasing in open quantum systems.

Contribution

It introduces a protocol to excite Josephson oscillations in an open Bose-Hubbard dimer and provides an analytical estimate for the decay time due to dephasing.

Findings

Oscillations can be initiated using a specific external driving protocol.

Decay of oscillations is primarily due to dephasing from particle number fluctuations.

An analytical expression for the decay time of Josephson oscillations is derived.

Abstract

We analyze Josephson's oscillation of Bose particles in the open (dissipative) Bose-Hubbard dimer. First, we excite the dimer from the vacuum state into a state suitable for observing the oscillation by using a special protocol for external driving. Next, we switch off the driving and observe the oscillation. It is shown that the main mechanism for the decay of Josephson's oscillation is the dephasing due to fluctuating number of particles in open systems. An analytical estimate for the decay time is obtained.