Tracking spin and charge with spectroscopy in spin-polarised 1D systems

TL;DR

This paper studies the spectral function of a 1D strongly interacting fermion chain, revealing how spin imbalance affects spinon and holon excitations, and proposes spectroscopic methods for experimental identification.

Contribution

It introduces a spectroscopic approach to distinguish spinon and holon excitations in spin-polarized 1D systems, applicable to cold atom and condensed matter experiments.

Findings

Spin imbalance shifts the spectral response from spinon to holon peaks.

Spectroscopic signatures can identify spin-charge separation in 1D systems.

Method applies to both electronic and cold atomic gas setups.

Abstract

We calculate the spectral function of a one-dimensional strongly interacting chain of fermions, where the response can be well understood in terms of spinon and holon excitations. Upon increasing the spin imbalance between the spin species, we observe the single-electron response of the fully polarised system to emanate from the holon peak while the spinon response vanishes. For experimental setups that probe one-dimensional properties, we propose this method as an additional generic tool to aid the identification of spectral structures, e.g. in ARPES measurements. We show that this applies even to trapped systems having cold atomic gas experiments in mind.