Year: 2004
Type: article
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 $(\ensuremath{-}g{\ensuremath{\mu}}_{\mathrm{B}})c/L$ at zero temperature, provided the staggered correlation length $\ensuremath{\xi}$ 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 ${\ensuremath{\mu}}_{\mathrm{B}}$ is the Bohr magneton. For $\ensuremath{\xi}\ensuremath{\ll}L$ the current is exponentially suppressed.
Source: Physical Review B
Authors: Florian Schütz, Marcus Kollar, Peter Kopietz
Institution: Goethe University Frankfurt
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2055904455