Regensburg 2007 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 21: Solids at Low Temperature - Poster Session
TT 21.14: Poster
Mittwoch, 28. März 2007, 14:00–17:45, Poster A
Numerical simulation of the influence of nuclear moments on two- pulse polarization echoes in glassy glycerol — •Gudrun Fickenscher1, Masoomeh Bazrafshan1, Kathrin Reinhold1, Marek Bartkowiak2, Herbert Zimmermann3, Andreas Fleischmann1, and Christian Enss1 — 1Kirchhoff-Institut für Physik-Universität Heidelberg — 2Forschungszentrum-Rossendorf-Dresden — 3Max-Plank-Institut für Medizinische Forschung-Heidelberg
At low temperatures - below a few Kelvin - the properties of glasses are dominated by the tunneling motion of atomic tunneling systems in a double well potential. A few years ago it was shown that tunneling particles having a nuclear qudrupole moment experiencing electric field gradient cause magnetic field effects in non-magnetic glasses. This effect is observed using the method of two pulse polarization echoes, looking at the magnetic field dependence as well as the time dependence of echo amplitude. Recently, we observed that the presence of interacting magnetic dipole moments leads to qualitatively similar effects on a smaller magnetic scale. In this work we developed numerical techniques to simulate the amplitude of the two- pulse polarization echo, having flexibility of including any number of dipole and quadrupole moments corresponding to H and D atoms in partially deuterated samples. The simulations are done assuming a specific microscopic model of tunneling motion with specific distributions for tunneling parameters. The results of such simulations are presented comparing to experimental data.