Ultrafast control of spin-orbital separation probed with time-resolved RIXS

TL;DR

This paper demonstrates how time-resolved RIXS can be used to reversibly control spin-orbital separation in a quasi-one-dimensional Mott insulator, revealing new possibilities for manipulating many-body quantum states with laser fields.

Contribution

It provides a theoretical analysis showing that external electric fields can reversibly modify spinon and orbiton dynamics in Sr$_2$CuO$_3$ via the effective $t-J$ model, enabling control of many-body physics.

Findings

External electric fields can reversibly alter the $t-J$ model parameters.

Strong driving amplitudes can qualitatively change the RIXS spectrum.

Reversible control of spin-orbital dynamics is feasible with laser fields.

Abstract

Quasi-one-dimensional systems exhibit many-body effects elusive in higher dimensions. A prime example is spin-orbital separation, which has been measured by resonant inelastic X-ray scattering (RIXS) in Sr$_2$CuO$_3$. Here, we theoretically analyze the time-resolved RIXS spectrum of Sr$_2$CuO$_3$ under the action of a time-dependent electric field. We show that the external field can reversibly modify the parameters in the effective $t-J$ model used to describe spinon and orbiton dynamics in the material. For strong driving amplitudes, we find that the spectrum changes qualitatively as a result of reversing the relative spinon to orbiton velocity. The analysis shows that in general, the spin-orbital dynamics in Mott insulators in combination with time-resolved RIXS should provide a suitable platform to explore the reversible control of many-body physics in the solid with strong laser fields.