SKM 2021 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 3: Poster Session I
HL 3.17: Poster
Montag, 27. September 2021, 10:00–13:00, P
Temperature and magnetic field dependent noise measurements in quantum rings — •Birkan Düzel1, Olivio Chiatti1, Sven S. Buchholz1, Andreas D. Wieck2, Dirk Reuter3, and Saskia F. Fischer1 — 1Novel Materials Group, Humboldt-Universität zu Berlin, 10099 Berlin, Germany — 2Angewandte Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany — 3Optoelektronische Materialien und Bauelemente, Universität Paderborn, 33098 Paderborn, Germany
Phase-coherent transport of electrons and resulting interference effects offer a way to characterize systems.
Noise measurements can be used to determine system properties, such as the electron temperature Te. White noise exceeding the expected thermal noise has been reported in quantum ring structures [1]. The presented model suggests that the excess noise is caused by a correlation of noise sources in quantum rings, because said excess noise can only be observed when two interfering electron pathes exist.
This work investigates the dependence of the excess noise in quantum rings on the bath temperature and applied magnetic field. Noise measurements in AlxGaxAs/GaAs-based etched quantum rings are performed in equlibrium with bath temperatures ranging from 15 mK to 12 K and magnetic fields ranging from -50 mT to 50 mT.
The aim is to quantify the relationship between the phase coherence length of the electrons and the excess noise in the quantum ring structures.
[1] C. Riha et al., Appl. Phys. Lett. 117, 063102 (2020).