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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:12 |
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Conference: Bucharest University Faculty of Physics 2005 Meeting
Section: Electricity and Biophysics
Title:
Quantum Rings Produced by Nanolithography with an Atomic Force Microscope
Authors:
V. A. Antohe, *A. Muhle, *R. J. Haug
Affiliation:
University of Bucharest, Faculty of Physics, P.O.Box: MG-11, Bucharest - Magurele, 077125, Romania
*University of Hannover, Nanostructures Department, Hannover, Germany
E-mail
vlad_antohe@yahoo.com
Keywords:
Nanostructures, 2DEG, AFM, Quantum Rings
Abstract:
The nanoparticles and the nanostructures have generated much interest in recent years, mainly as a result of quantum confinement effects, a range of intriguing properties of such structures and new applications opened up in all the electronic fields. Two key concepts in solid state physics have enabled the direct fabrication of small quantum structures, investigated in this work. The first is the invention of modulation doped GaAs/AlGaAs – heterostructures, allowing the production of high-quality two-dimensional electron gases (2DEG). The second miliestone was the development of the Scanning Probe Microscope (STM, AFM), which allowed the investigation of surfaces with atomic resolution and the changing of surfaces properties, also. In this paper we shall combine 2DEG and Atomic Force Microscope (AFM) lithography for realization of mesoscopic devices especially Quantum Rings. We have studied different phenomena in our rings, such as: Schubnikov-de Haas oscillations (calculating the density and the mobility of electrons in 2DEG) and Aharonov-Bohm effect (finding the electronic diameters in our rings). The measurements were performed at very low temperatures (about 10 mK) and/or in magnetic field ranging from 0 to 500 mT.
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