title: Coherent spin-current oscillations in transverse magnetic fields.
abstract: We address the coherence of the dynamics of spin-currents with components transverse to an external magnetic field for the spin-1/2 Heisenberg chain. We study current autocorrelations at finite temperatures and the real-time dynamics of currents at zero temperature. Besides a coherent Larmor oscillation, we find an additional collective oscillation at higher frequencies, emerging as a coherent many-magnon effect at low temperatures. Using numerical and analytical methods, we analyze the oscillation frequency and decay time of this coherent current-mode versus temperature and magnetic field.
authors: Institute for Theoretical Physics, Technical University Braunschweig, Braunschweig, Germany. r.steinigeweg@tu-bs.de
authors: Robin
authors: R
authors: Steinigeweg
authors: Stephan
authors: S
authors: Langer
authors: Fabian
authors: F
authors: Heidrich-Meisner
authors: Ian P
authors: IP
authors: McCulloch
authors: Wolfram
authors: W
authors: Brenig