Dynamical properties of a driven dissipative dimerized S=1/2 chain

We consider the dynamical properties of a gapped quantum spin system coupled to the electric field of a laser, which drives the resonant excitation of specific phonon modes that modulate the magnetic interactions. We deduce the quantum master equations governing the time-evolution of both the lattice and spin sectors, by developing a Lindblad formalism with bath operators providing an explicit description of their respective phonon-mediated damping terms. We investigate the nonequilibrium steady states (NESS) of the spin system established by a continuous driving, delineating parameter regimes in driving frequency, damping, and spin-phonon coupling for the establishment of physically meaningful NESS and their related nontrivial properties. Focusing on the regime of generic weak spin-phonon coupling, we characterize the NESS by their frequency and wave-vector content, explore their transient and relaxation behavior, and discuss the energy flow, the system temperature, and the critical role of the type of bath adopted. Our study lays a foundation for the quantitative modeling of experiments currently being designed to control coherent many-body spin states in quantum magnetic materials.

Automated summary

This study investigates the dynamical properties of a gapped quantum spin system coupled to a laser electric field, driving resonant excitation of specific phonon modes modulating the magnetic interactions. By developing quantum master equations governing the time-evolution of both lattice and spin sectors, using a Lindblad formalism, the study explores nonequilibrium steady states (NESS) of the spin system and their related nontrivial properties. Focus is placed on the regime of weak spin-phonon coupling, characterizing the NESS by their frequency and wave-vector content, exploring their transient and relaxation behavior, and discussing the energy flow, system temperature, and critical role of the type of bath adopted.