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Oct 15 – 20, 2017
Harrison Hot Springs
Canada/Pacific timezone

Hunting the nedm by random walks

Oct 18, 2017, 4:35 PM
Harrison Hot Springs

Harrison Hot Springs

100 Esplanade Avenue, Harrison Hot Springs, BC Canada V0M 1K0
Oral Systematic effects WeAf2


Prof. Robert Golub (NCSU)


The behavior of a spin undergoing Larmor precession in the presence of fluctuating fields is of interest to workers in many fields. Particles making random walks in inhomogeneous fields see time fluctuating fields which cause frequency shifts and relaxation which are related to their power spectrum, which can be determined by taking the Fourier transform of the auto-correlation functions of the field fluctuations. Recently we have shown how to calculate these correlation functions for all values of mean free path (ballistic to diffusive motion) in finite bounded regions, using the model of persistent continuous time random walks (CTRW) for particles subject to scattering by fixed (frozen) scattering centers so that the speed of the moving particles is not changed by the collisions. Here we show how scattering with energy exchange from an ensemble of scatterers in thermal equilibrium can be incorporated into the CTRW. . Our results for the velocity autocorrelation function show a long time tail which we also obtain from conventional di usion theory, with the same power, independent of dimensionality. Our results are valid for any Markovian scattering kernel as well as any kernel based on a scattering cross section ~1/v.

Funding Agency



Primary author

Prof. Robert Golub (NCSU)

Presentation materials