Tunable spinful matter wave valve

TL;DR

This paper proposes a tunable spinful matter wave valve using a localized spin-orbit-coupled Bose-Einstein condensate, enabling control over spin-dependent transport, including transparency, splitting, blockade, and spin conversion.

Contribution

It introduces a novel method to control spinful matter wave transport via localized spin-orbit coupling, allowing for spin switcher, beam-splitter, isolator, and converter functionalities.

Findings

Achieved conditions for spin-dependent transparency and blockade.

Maximized spin state conversion in specific conditions.

Demonstrated potential for applications in spintronics and magnetism.

Abstract

We investigate the transport problem that a spinful matter wave is incident on a strong localized spin-orbit-coupled Bose-Einstein condensate in optical lattices, where the localization is admitted by atom interaction only existing at one particular site, and the spin-orbit coupling arouse spatial rotation of the spin texture. We find that tuning the spin orientation of the localized Bose-Einstein condensate can lead to spin-nonreciprocal / spin-reciprocal transport, meaning the transport properties are dependent on / independent of the spin orientation of incident waves. In the former case, we obtain the conditions to achieve transparency, beam-splitting, and blockade of the incident wave with a given spin orientation, and furthermore the ones to perfectly isolate incident waves of different spin orientation, while in the latter, we obtain the condition to maximize the conversion of different spin states. The result may be useful to develop a novel spinful matter wave valve that integrates spin switcher, beam-splitter, isolator, and converter. The method can also be applied to other real systems, e.g., realizing perfect isolation of spin states in magnetism, which is otherwise rather difficult.