Giant Resonant Self-Blocking in Magnetophononically Driven Quantum Magnets

TL;DR

This paper reveals a giant self-blocking effect in magnetophononics where the spin system limits phonon energy absorption, enabling control over spin-phonon states in quantum magnets with strong spin-phonon coupling.

Contribution

It uncovers the giant self-blocking phenomenon in driven quantum magnets and models its effects using quantum master equations, advancing understanding of spin-phonon interactions.

Findings

Self-blocking limits phonon energy absorption in driven quantum magnets.

Formation of mutually repelling hybrid spin-phonon states.

Control over nonequilibrium spin excitation band renormalization.

Abstract

Magnetophononics, the modulation of magnetic interactions by driven infrared-active lattice excitations, is emerging as a key mechanism for the ultrafast dynamical control of both semiclassical and quantum spin systems by coherent light. We demonstrate that, in a quantum magnetic material with strong spin-phonon coupling, resonances between the driven phonon and the spin excitation frequencies exhibit a giant self-blocking effect. Instead of absorbing more energy, the spin system acts as a strong brake on the driven phonon, causing it to absorb only a tiny fraction of the power available from the laser. Using the quantum master equations governing the nonequilibrium steady states of the coupled spin-lattice system, we show how self-blocking dominates the dynamics, demonstrate the creation of mutually repelling hybrid spin-phonon states, and control the nonequilibrium renormalization of the lattice-driven spin excitation band.