From deconfined spinons to coherent magnons in an antiferromagnetic Heisenberg chain with long range interactions

We study the nature of the excitations of an antiferromagnetic (AFM) Heisenberg chain with staggered long range interactions using the time-dependent density matrix renormalization group method and by means of a multi-spinon approximation. The chain undergoes true symmetry breaking and develops long range order, transitioning from a gapless spin liquid to a gapless ordered AFM phase. The spin dynamic structure factor shows that the emergence of Neel order can be associated to the formation of bound states of spinons that become coherent magnons. The quasiparticle band leaks out from the two-spinon continuum that is pushed up to higher energies. Our physical picture is also supported by an analysis of the behavior of the excitations in real-time.

Automated summary

In this study, the nature of excitations in an antiferromagnetic Heisenberg chain with staggered long range interactions was investigated using numerical methods and a multi-spinon approximation. It was found that the emergence of Neel order can be explained by the behavior of the spin dynamic structure factor. The chain undergoes true symmetry breaking and develops long range order, transitioning to a gapped ordered antiferromagnetic phase.