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Biomedical subjects

B N Harmon

Publications and source records attributed to B N Harmon.

2 recordsLinked to original sources
PubMed2003

Quantum oscillations without quantum coherence.

We study numerically the damping of quantum oscillations and the dynamics of the density matrix in model many-spin systems decohered by a spin bath. We show that oscillations of some density matrix elements can persist with considerable amplitude long after other elements, along with the entropy, have come close to saturation, i.e., when the system has been decohered almost completely. The oscillations exhibit very slow decay, and may be observable in experiments.

Journal Article↗
PubMed2003

Length scale coupling for nonlinear dynamical problems in magnetism.

The dynamics of real magnets is often governed by several interacting processes taking place simultaneously at different length scales. For dynamical simulations, the relevant length scales should be coupled, and the energy transfer accurately described. We show that in this case the micromagnetic theory is not always reliable. We present a coarse-graining approach applicable to nonlinear problems, which provides a unified description of all relevant length scales, allowing a smooth, seamless coupling. The simulations performed on model systems show that the coarse-graining approach achieves nearly the precision of all-atom simulations.

Journal Article↗