Generation of chiral solitons in antiferromagnetic chains by a quantum quench

TL;DR

This paper demonstrates how a quantum quench in an antiferromagnetic chain can generate stable, counter-propagating chiral solitons, with potential applications in spin-Peierls materials and ultracold-atom systems.

Contribution

It introduces a method to create and analyze chiral solitons in antiferromagnetic chains through quantum quenches, combining bosonization and numerical simulations.

Findings

Initial static soliton evolves into two chiral states

Chiral states interfere to produce specific spin expectation values

Generated states remain stable over time

Abstract

We analyze the time evolution of a magnetic excitation in a spin-1/2 antiferromagnetic Heisenberg chain after a quantum quench. By a proper modulation of the magnetic exchange coupling, we prepare a static soliton of total spin 1/2 as an initial spin state. Using bosonization and a numerical time dependent density matrix renormalization group algorithm, we show that the initial excitation evolves to a state composed of two counter-propagating chiral states, which interfere to yield <S^z> = 1/4 for each mode. We find that these dynamically generated states remain considerably stable as time evolution is carried out. We propose spin-Peierls materials and ultracold-atom systems as suitable experimental scenarios in which to conduct and observe this mechanism.