Simulations of Non-linear Spin Dynamics in Spin Polarized Dilute 3He–4He Mixtures
Studies of spin dynamics of highly polarized dilute mixtures of 3He in superfluid 4He have been performed by various researchers over the past three decades. One series of experiments performed at Cornell University in the early 1990’s revealed a novel long timescale excitation. We present the numerical solution of the non-linear Leggett spin dynamics equation in one spatial dimension subject to boundary conditions consistent with the Cornell experiments. Experimentally observed phenomena are composed of trains of bursts in the transverse magnetization lasting several seconds. The simulations capture the time evolution of the individual bursts localized in time. Preliminary results of two dimensional simulations are also presented.
KeywordsHelium mixtures Fermi liquid NMR Non-linear Spin dynamics
The authors thank the Norman Hackerman Advanced Research Program of the State of Texas under grant No. 010366-0137-2009. They are also grateful to the National Science Foundation (Award number 1209255) for their support of this work. They are grateful to Dr. Geoffrey Nunes and Prof. Erich Mueller for illuminating advice and discussions. Figures 1 and 2 were adapted from the Ph.D. thesis of Geoffrey Nunes [6, 14].