Controlling superfluid flows using dissipative impurities

TL;DR

This paper introduces a protocol to manipulate superfluid flows in a one-dimensional Bose gas using noisy point contacts, revealing three dynamical regimes and potential for atomtronic applications.

Contribution

It identifies and characterizes three distinct dynamical phases in superfluid flow control via dissipative impurities, including a novel soliton emission regime.

Findings

Three dynamical phases identified: linear response, Zeno suppression, soliton emission.

Noise tuning enables control and stabilization of superfluid transport.

Potential for atomtronic superfluid-current sources.

Abstract

We propose and analyze a protocol to create and control the superfluid flow in a one dimensional, weakly interacting Bose gas by noisy point contacts coupled to the density of the bosons. Considering first a single contact in a static or moving condensate, we identify three different dynamical phases: I. a linear response regime, where the noise induces a coherent flow in proportion to the strength of the noise accompanied by a counterflow of the normal component of the gas, II. a Zeno regime with suppressed currents and negative differential current to noise characteristics, and III. for a non-vanishing relative velocity, a regime of continuous soliton emission. The velocity of the condensate at the dissipative impurity determines the threshold for Zeno suppression of the current through the point contact, and the onset of the non-stationary regime of soliton "shooting" from the defect. Generalizing to two point contacts in a condensate at rest we show that noise tuning can be employed to control, stabilize or eventually shunt the superfluid transport of particles along the segment which connects them, with perspectives for an atomtronic analogue of a superfluid-current source for studying quantum transport phenomena.