Quantum hydrodynamics of spin winding
Abstract
An easyplane spin winding in a quantum spin chain can be treated as a transport quantity, which propagates along the chain but has a finite lifetime due to phase slips. In a hydrodynamic formulation for the winding dynamics, the quantum continuity equation acquires a source term due to the transverse vorticity flow. The latter reflects the phase slips and generally compromises the global conservation law. A linearresponse formalism for the nonlocal winding transport then reduces to a Kubo response for the winding flow along the spin chain, in conjunction with the parasitic vorticity flow transverse to it. Onedimensional topological hydrodynamics can be recovered when the vorticity flow is asymptotically small. Starting with a microscopic spinchain formulation, we focus on the asymptotic behavior of the winding transport based on the renormalized sineGordon equation, incorporating phase slips as well as Gilbert damping. A generic electrical device is proposed to manifest this physics. We thus suggest winding conductivity as a tangible concept that can characterize lowenergy dynamics in a broad class of quantum magnets.
 Publication:

arXiv eprints
 Pub Date:
 September 2020
 arXiv:
 arXiv:2010.00144
 Bibcode:
 2020arXiv201000144T
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 9 pages, 2 figures