Spin-charge separated quasiparticles in one dimensional quantum fluids

TL;DR

This paper explores the dynamical response of one-dimensional quantum fluids with spin-charge separation, emphasizing the importance of fermionic holons and spinons due to spectral nonlinearity, and develops a mobile impurity model to analyze threshold singularities.

Contribution

It introduces a mobile impurity model for spinon thresholds and investigates the realization of noninteracting holons and spinons in lattice models using DMRG.

Findings

Formulated and solved a mobile impurity model for spinon thresholds.

Demonstrated the significance of fermionic holons and spinons due to spectral nonlinearity.

Explored the possibility of realizing noninteracting holons and spinons in microscopic models.

Abstract

We revisit the problem of dynamical response in spin-charge separated one dimensional quantum fluids. In the framework of Luttinger liquid theory, the dynamical response is formulated in terms of noninteracting bosonic collective excitations carrying either charge or spin. We argue that, as a result of spectral nonlinearity, long-lived excitations are best understood in terms of generally strongly interacting fermionic holons and spinons. This has far reaching ramifications for the construction of mobile impurity models used to determine threshold singularities in response functions. We formulate and solve the appropriate mobile impurity model describing the spinon threshold in the single-particle Green's function. Our formulation further raises the question whether it is possible to realize a model of noninteracting fermionic holons and spinons in microscopic lattice models of interacting spinful fermions. We investigate this issue in some detail by means of density matrix renormalization group (DMRG) computations.