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Q: Fachverband Quantenoptik und Photonik
Q 5: Quantum Technologies I
Q 5.6: Vortrag
Montag, 14. März 2022, 15:15–15:30, Q-H13
Coupling function from bath density of states — •Somayyeh Nemati1, Carsten Henkel1, and Janet Anders1, 2 — 1University of Potsdam, Institut für Physik und Astronomie, 14476 Potsdam, Germany. — 2Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK.
Quantum technologies face many challenges, often arising due to the unavoidable coupling of any system to its environment. Modelling of such open quantum systems requires parameters and the functional form of this coupling, which critically affects the system dynamics [1,2]. However, beyond relaxation rates, realistic parameters for specific environments or materials are rarely known.
Here [3] we present a method of inferring the coupling function between a generic system and its bosonic (e.g., phononic) environment from the experimentally measurable density of states (DOS). The DOS of the well-known Debye model for three-dimensional solids is shown to be equivalent to an Ohmic bath. We further match a real phonon DOS to a series of Lorentzian coupling functions, and determine parameters for gold, yttrium iron garnet (YIG) and iron. The results also illustrate the functional shape of memory kernels. The proposed method may predict more accurately the relaxation of spin systems that are damped by coupling to the crystal lattice.
[1] Zou H. M., Liu R., Long D., Yang J., Lin D., Phys. Scr. 95, 085105 (2020).
[2] Anders J., Sait C. R. J., Horsley S. A. R., arXiv:2009.00600.
[3] Nemati S., Henkel C., Anders J., arXiv:2112.04001.