Persistent spin currents in mesoscopic Haldane gap spin rings
Mesoscale and Nanoscale Physics
2009-11-10 v2 Strongly Correlated Electrons
Abstract
Using a modified spin-wave approach, we show that in the presence of an inhomogeneous magnetic field or an in plane inhomogeneous electric field a mesoscopic antiferromagnetic Heisenberg ring with integer spin (i.e., a Haldane gap system) exhibits a persistent circulating spin current. Due to quantum fluctuations the current has a finite limit on the order of -g mu_B c/L at zero temperature, provided the staggered correlation length xi exceeds the circumference L of the ring, in close analogy to ballistic charge currents in mesoscopic normal metal rings. Here c is the spin-wave velocity, g is the gyromagnetic ratio and mu_B is the Bohr magneton. For xi<<L the current is exponentially suppressed.
Cite
@article{arxiv.cond-mat/0308230,
title = {Persistent spin currents in mesoscopic Haldane gap spin rings},
author = {Florian Schuetz and Marcus Kollar and Peter Kopietz},
journal= {arXiv preprint arXiv:cond-mat/0308230},
year = {2009}
}
Comments
7 pages, 4 figures, published version