Exact spin dynamics of the 1/r^2 supersymmetric t-J model in a magnetic field

TL;DR

This paper analytically derives the spin structure factor for a one-dimensional supersymmetric t-J model with 1/r^2 interaction, revealing strong spin-charge separation and specific contributions from spinons and magnons.

Contribution

It provides an exact analytical solution for the spin dynamics of the supersymmetric t-J model in a magnetic field, highlighting spin-charge separation and specific excitation contributions.

Findings

Strong spin-charge separation in spin dynamics

Structure factor independent of electron density at small momentum

Only two spinons and one magnon contribute in the thermodynamic limit

Abstract

The dynamical spin structure factor S^{zz}(Q,omega) in the small momentum region is derived analytically for the one-dimensional supersymmetric t-J model with 1/r^2 interaction. Strong spin-charge separation is found in the spin dynamics. The structure factor S^{zz}(Q,omega) with a given spin polarization does not depend on the electron density in the small momentum region. In the thermodynamic limit, only two spinons and one antispinon (magnon) contribute to S^{zz}(Q,omega). These results are derived via solution of the SU(2,1) Sutherland model in the strong coupling limit.