2004/05/31 by F. Schütz, Florian Schuetz, Peter Kopietz +1 · 1 citation
Physics and Astronomy · #Magnetic properties of thin films #Quantum and electron transport phenomena #Quantum many-body systems #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1140/epjb/e2004-00348-9
published as Eur. Phys. J. B 41, 557 (2004) · 4 pages, 1 figure, published version
openalex publication_date 2004/10/01 · arxiv created 2004/11/16 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We discuss the proper definition of the spin current operator in Heisenberg magnets subject to inhomogeneous magnetic fields. We argue that only the component of the naive "current operator" Jij Si x Sj in the plane spanned by the local order parameters <Si> and <Sj> is related to real transport of magnetization. Within a mean field approximation or in the classical ground state the spin current therefore vanishes. Thus, finite spin currents are a direct manifestation of quantum correlations in the system.