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TT: Fachverband Tiefe Temperaturen
TT 19: Poster Session: Disordered Quantum Systems
TT 19.3: Poster
Montag, 1. April 2019, 15:00–18:30, Poster D
Influence of Nuclear Quadrupole Moments on the Dielectric Properties of Amorphous Solids in the MHz-regime at Low Temperatures — •Lukas Münch, Timothy Jay Herbst, Alexander Werner, Benedikt Frey, Andreas Fleischmann, Andreas Reiser, and Christian Enss — Kirchhoff-Institute for Physics, Heidelberg University, D-69120 Heidelberg
The low temperature behavior of amorphous solids is mainly governed by atomic tunneling systems and can be described in many cases by the phenomenological standard tunneling model (STM). Acoustic and dielectric measurements however have also revealed deviations from the STM. These led to a number of refinements of the STM, among others for glasses containing elements with large nuclear quadrupole moments. In order to further investigate the influence of nuclear quadrupole moments, we performed dielectric measurements in the MHz regime, using an LC resonator filled with the samples as dielectric material. =0pt
In a first attempt, we performed measurements on two brominated samples with a well known quadrupole splitting of about 12 mK, which is thermally accessible in our experiment. For both samples we observe slight deviations towards the quadrupole splitting energy. In a second experiment we stimulated the quadrupole moments of As2S3 directly by tuning the resonance frequency of the LC resonator to the sample’s quadrupole splitting of 72 MHz. Comparing the result to a measurement with a slightly detuned excitation frequency, we are able to relate existing deviations to the nuclear quadrupole moments.