Generation of chiral solitons in antiferromagnetic chains by a quantum quench

Abstract

We analyze the time evolution of a magnetic excitation in a spin-12 antiferromagnetic Heisenberg chain after a quantum quench. By a proper modulation of the magnetic exchange coupling, we prepare a static soliton of total spin 12 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 counterpropagating chiral states, which interfere to yield 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. © 2013 American Physical Society.