Coherent Quantum Phase Slip in two-component bosonic Atomtronic Circuits

TL;DR

This paper explores coherent quantum phase slips in a two-component Bose gas in a toroidal trap, demonstrating superposition of current states and proposing its use as a qubit in quantum computing.

Contribution

It shows that a two-component Bose gas can exhibit coherent quantum phase slips and remain in superpositions, mapping onto a Josephson problem, with practical implementation for qubits.

Findings

System remains in superposition of current states during dynamics

System can be mapped onto a linear Josephson problem

Feasible for experimental realization with Rb-87 atoms

Abstract

Coherent Quantum Phase Slip consists in the coherent transfer of vortices in superfluids. We investigate this phenomenon in two miscible coherently coupled components of a spinor Bose gas confined in a toroidal trap. After imprinting different vortex states on each component, we demonstrate that during the whole dynamics the system remains in a linear superposition of two current states in spite of the non-linearity and can be mapped onto a linear Josephson problem. We propose this system as a good candidate for the realization of a Mooij-Harmans qubit and remark its feasibility for implementation in current experiments with $^{87}\mbox{Rb}$, since we have used values for the physical parameters currently available in laboratories.