# Regensburg 2019 – wissenschaftliches Programm

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# DY: Fachverband Dynamik und Statistische Physik

## DY 37: Quantum Chaos

### DY 37.6: Vortrag

### Mittwoch, 3. April 2019, 16:45–17:00, H6

**Motional narrowing in microwave graphs** — •Tobias Hofmann^{1}, Aimaiti Rehemanjiang^{1}, Ulrich Kuhl^{1,2}, and Hans-Jürgen Stöckmann^{1} — ^{1}Fachbereich Physik, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany — ^{2}InPhyNi, Université Côte d’Azur, 06100 Nice, France

Motional narrowing is a well-known phenomenon in nuclear magnetic resonance (NMR) spectroscopy and is caused by rapidly moving atoms in an inhomogeneous magnetic environment [1]. If there are just two sites involved, realized e. g. by a molecular flip between two geometries or configurational changes in a glassy network, an analytical solution is known [2]. Also in superconducting qubits with two stochastically fluctuating energies an analogue of the effect could be seen [3].

To simulate the effects of motional averaging and motional narrowing in microwave graphs stochastic switching has to be employed. This means to flip a resonance frequency of the graph between two values stochastically. The flip frequency is thereby comparable to or greater than the energy difference of the two resonance frequencies involved. By using a special diode circuit this frequency regime of typically some 10 MHz becomes accessible and the effects of motional averaging and motional narrowing can be observed in microwave graphs. The setup and experimental results will be presented.

[1] A. Abragam, Principles of Nuclear Magnetism, University Press Oxford 1961

P. W. Anderson, J. Phys. Soc. Jpn. **9**, 316 (1954)

J. Li et al., Nat. Comm. **4**, 1420 (2013)