SKM 2023 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 16: Poster: Transport

TT 16.1: Poster

Montag, 27. März 2023, 15:00–18:00, P2/OG4

Asymmetric and spatially resolved power dissipation in quantum transport — •Nico Leumer — Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France

Dissipation is a natural byproduct of quantum transport caused by various inelastic scattering events of electrons and their lost energy stimulates in turn the temperature profile of the underlying bulk material. Importantly though, electronic current may run only through a narrow part of the sample as, for instance, happens in the quantum Hall regime of graphene due to chiral edge channels (1); thus, dissipation has to be seen as a local quantity. The still rather recent invention of the Squid-on-tip technique in 2016 (2), paved the way to experimental access this challenge, where the temperature increases by merely a few hundred micro Kelvin on length scales of the order of nanometers.

Quantum point contacts (QPC’s) are of particular interest in nanoscale transport, as electrons experience now a -perhaps energy dependent- transmission probability. On a hand waving level, QPC’s increase the resistance electrons face from the sample locally, which is accompanied by areas of higher dissipation. In our recent project, we predict where and how much power is dissipated.

[1] A. Marguerite et al., Nature 575, 628 (2019)

[2] D. Halbertal et al., Nature 539, 407 (2016)