Laser-induced coherent control of an electronic nematic quantum phase transition

TL;DR

This paper presents a laser-based method to control and study electronic nematic quantum phase transitions in materials like FeSe, minimizing heating effects through phonon-mediated interactions.

Contribution

It introduces a novel ultrafast laser technique that uses off-resonant pulses to coherently control nematic phases via phonon coupling, reducing heating in quantum materials.

Findings

Laser pulses can induce and suppress nematic order in FeSe.

Phonon coupling mediates interactions and reduces heating effects.

Method enables ultrafast control of quantum phase transitions.

Abstract

Ultrafast techniques have emerged as promising methods to study and control quantum materials. To maintain the quantum nature of the systems under study, excess heating must be avoided. In this work, we demonstrate a method that employs the nonequilibrium laser excitation of planar stretching optical phonons in tetragonal systems to quench an electronic nematic state across a quantum phase transition. Appropriately tuned off-resonant pulses can perform a quantum quench of the system either into the nematic phase (red detuning) or out of it (blue detuning). The nonlinear coupling of this phonon mode to nematicity not only mediates interactions in the nematic channel, but it also suppresses heating effects. We illustrate the applicability of our general results by considering the microscopic parameters of the nematic unconventional superconductor FeSe.