Year: 2023
Type: article
Abstract: We measure electron transport through point contacts in an electron gas in AlGaAs/GaAs heterostructures and graphene for a range of temperatures, magnetic fields, and electron densities. We find a magnetoconductance peak around $B=0$. With increasing temperature, the width of the peak increases monotonically, while its amplitude first increases and then decreases. For GaAs point contacts the peak is particularly sharp at relatively low temperatures $T\ensuremath{\approx}1.5\phantom{\rule{0.16em}{0ex}}\mathrm{K}$: the curve rounds on a scale of a few tens of microteslas, hinting at length scales of several millimeters for the corresponding scattering processes. We propose a model based on the transition between different transport regimes with increasing temperature: from ballistic transport to few electron-electron scatterings to hydrodynamic superballistic flow to hydrodynamic Poiseuille-like flow. The model is in qualitative and, in many cases, quantitative agreement with the experimental observations.
Source: Physical Review Research
Institutions: ETH Zurich, Laboratory for Solid State Physics, Central European Institute of Technology, Brno University of Technology, Columbia University, Massachusetts Institute of Technology, Harvard University, National Institute for Materials Science, Research Center for Materials Nanoarchitectonics
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,625
Funders: National Science Foundation, Graphene Flagship, European Commission, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Eidgenössische Technische Hochschule Zürich, Horizon 2020 Framework Programme, Japan Society for the Promotion of Science, National Center of Competence in Research Quantum Science and Technology, H2020 European Research Council, HORIZON EUROPE Marie Sklodowska-Curie Actions
Awards: G2559794857, G4196313753, G434337789, G4722835768, Entropy in engineered quantum systems - Mesoscopic thermodynamics of correlated quantum states, G4937468798, G5783601166, G6239784780, G6664495284, G7944295140, 糖化合物の CMR, Pmr, CD, ORD による立体構造解析の研究, QUantum Electronics Science and TECHnology training, Synthesis of high quality single crystals for sience of Boron Nitride, G887491987
OpenAlex ID: W4387956736