Emergence of chirality by multipole interconversion

TL;DR

This paper explores how chirality emerges in spin-active electronic states through multipole interconversion, linking fundamental concepts to material and field phenomena, with examples from physics and chemistry.

Contribution

It introduces the concept of chirality emergence via multipole interconversion and extends chirality understanding to material-field composites.

Findings

Electronic toroidal monopole $G_0$ measures chirality.

Chirality can emerge from achiral degrees of freedom.

Interference among multiple chiralities affects handedness phenomena.

Abstract

A clear understanding of chirality in spin-active electronic states is discussed in order to address confusions about chiral effects recently discovered in materials science. Electronic toroidal monopole $G_0$ can serve as a measure of chirality in this categorization, which can be clearly related to the chiral density operator in the Dirac equation. We extend the concepts of chirality not only to those of materials but also to those of physical fields, and to material-field composites. Additionally, we illustrate specific examples from physics and chemistry that demonstrate the process of acquiring chirality through the combination of seemingly achiral degrees of freedom, which we term the emergence of chirality. Interference among multiple chiralities exhibiting phenomena specific to handedness is also discussed.