Role of transverse-momentum currents in the optical Magnus effect in free space

TL;DR

This paper introduces a vector field model demonstrating a polarization-dependent optical Magnus effect in free space, driven by transverse-momentum currents, without requiring light-matter interaction, and predicts its experimental observability.

Contribution

The study reveals a new polarization-dependent optical Magnus effect in free space linked to transverse-momentum currents, expanding understanding of light's angular momentum effects.

Findings

Optical polarization-dependent Magnus effect exists in free space.

Transverse-momentum currents are crucial for this effect.

The effect can be observed experimentally during wave propagation.

Abstract

We establish a general vector field model to describe the role of transverse-momentum currents in the optical Magnus effect in free space. As an analogy of the mechanical Magnus effect, the circularly polarized wave packet in our model acts as the rotating ball, and its rotation direction depends on the polarization state. Based on this model, we demonstrate the existence of an optical polarization-dependent Magnus effect which is significantly different from the conventional optical Magnus effect in that light-matter interaction is not required. Further, we reveal the relation between transverse-momentum currents and the optical Magnus effect, and find that such a polarization-dependent rotation is unavoidable when the wave packet possesses transverse-momentum currents. The physics underlying this intriguing effect is the combined contributions of transverse spin and orbital currents. We predict that this effect may be observed experimentally even in the propagation direction. These findings provide further evidence for the optical Magnus effect in free space and can be extrapolated to other physical systems.