The effect of dephasing and spin-lattice relaxation during the switching processes in quantum antiferromagnets

TL;DR

This paper presents a theoretical study on how dephasing and spin-lattice relaxation influence the stabilization of antiferromagnetic order after switching, using a quantum mean-field approach with environmental coupling.

Contribution

It introduces a time-dependent Schwinger boson mean-field theory combined with Lindblad formalism to analyze the effects of dephasing and relaxation during antiferromagnetic switching.

Findings

Spin-lattice relaxation leads to rapid convergence to steady-state.

Dephasing affects the interference of wave vectors.

Ultrafast switching is stabilized by relaxation processes.

Abstract

The control of antiferromagnetic order can pave the way to large storage capacity as well as fast manipulation of stored data. Here achieving a steady-state of sublattice magnetization after switching is crucial to prevent loss of stored data. The present theoretical approach aims to obtain instantaneous stable states of the order after reorienting the N\'eel vector in open quantum antiferromagnets using time-dependent Schwinger boson mean-field theory. The Lindblad formalism is employed to couple the system to the environment. The quantum theoretical approach comprises differences in the effects of dephasing, originating from destructive interference of different wave vectors, and spin-lattice relaxation. We show that the spin-lattice relaxation results in an exponentially fast convergence to the steady-state after full ultrafast switching.