Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2001-10-25
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
4 pages, 3 figures
Scientific paper
Currently, spin tunneling at very low temperatures is assumed to proceed as an incoherent sequence of events that take place whenever a bias field h(t) that varies randomly with time t becomes sufficiently small, as in Landau-Zener transitions. We study the behavior of a suitably defined coherence time t_p. Coherence effects become significant when t_p >= t_h$, where t_h is the correlation time for h(t). The theory of tunneling of Prokof'ev and Stamp (PS), which rests on the assumption that t_p <= t_h, is extended beyond this constraint. It is shown, both analytically and numerically, that t_p >= t_h when t_h*dh <= h, where dh is the rms deviation of h. Equations that give t_p and the tunneling rate as a function of t_h*dh both for t_h*dh>=h, where the theory of PS hold, and for t_h*dh <= h, where it does not, are derived.
Fernandez Julio F.
No associations
LandOfFree
Coherence in magnetic quantum tunneling does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Coherence in magnetic quantum tunneling, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coherence in magnetic quantum tunneling will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-359786