Time-resolved pure spin fractionalization and spin-charge separation in helical Luttinger liquid based devices

TL;DR

This paper proposes a setup using helical Luttinger liquids to time-resolve charge fractionalization, spin-charge separation, and pure spin fractionalization, leveraging spin-momentum locking and interactions without magnetic materials.

Contribution

It introduces a novel experimental scheme to observe spin-related phenomena in helical Luttinger liquids through electric time-resolved measurements.

Findings

Charge and spin fractionalization can be simultaneously observed.

Electric measurements can reveal spin-charge separation.

The setup is feasible with current technology.

Abstract

Helical Luttinger liquids, appearing at the edge of two-dimensional topological insulators, represent a new paradigm of one-dimensional systems, where peculiar quantum phenomena can be investigated. Motivated by recent experiments on charge fractionalization, we propose a setup based on helical Luttinger liquids that allows to time-resolve, in addition to charge fractionalization, also spin-charge separation and pure spin fractionalization. This is due to the combined presence of spin-momentum locking and interactions. We show that electric time-resolved measurements can reveal both charge and spin properties, avoiding the need of magnetic materials. Although challenging, the proposed setup could be achieved with nowadays technologies, promoting helical liquids as interesting playgrounds to explore the effects of interactions in one dimension.