An oscillating Casimir potential between two impurities in a spin-orbit coupled Bose-Einstein condensate

TL;DR

This paper investigates how spin-orbit coupling in a Bose-Einstein condensate induces an anisotropic, oscillating Casimir potential between impurities, leading to tunable non-central forces with potential applications in quantum control.

Contribution

It reveals the emergence of an anisotropic, oscillating Casimir potential in spin-orbit coupled BECs, a novel effect not previously characterized.

Findings

Oscillating Casimir potential with positive and negative parts

Potential depends on spin-orbit coupling strength

Induces non-central, tunable Casimir forces

Abstract

We study the Casimir potential between two impurities immersed in a spin-orbit coupled BoseEinstein condensate (BEC) with plane-wave order. We find that, by exchanging the virtual phonons/excitations, a remarkable anisotropic oscillating potential with both positive and negative parts can be induced between the impurities, with the period of the oscillation depending on the spin-orbit coupling strength. As a consequence, this would inevitably lead to a non-central Casimir force, which can be tuned by varying the strength of spin-orbit coupling . These results are elucidated for BECs with one-dimensional Raman-induced and two-dimensional Rashba-type SOC.