Drag of superfluid current in bilayer Bose systems

TL;DR

This paper investigates nondissipative superfluid drag in bilayer Bose gases, showing how it can control persistent currents and enable a Bose analog of the Josephson flux qubit, with potential applications in quantum devices.

Contribution

It introduces a theoretical framework for superfluid drag in bilayer Bose systems and explores its potential for quantum control and device implementation.

Findings

Drag current computed at various temperatures and density ratios.

Drag effect influences superfluid currents similarly to magnetic flux in superconductors.

Potential for implementing Bose analogs of superconducting qubits.

Abstract

An effect of nondissipative drag of a superfluid flow in a system of two Bose gases confined in two parallel quasi two-dimensional traps is studied. Using an approach based on introduction of density and phase operators we compute the drag current at zero and finite temperatures for arbitrary ratio of densities of the particles in the adjacent layers. We demonstrate that in a system of two ring-shape traps the "drag force" influences on the drag trap in the same way as an external magnetic flux influences on a superconducting ring. It allows to use the drag effect to control persistent current states in superfluids and opens a possibility for implementing a Bose analog of the superconducting Josephson flux qubit.