Fabrication and Characterisation of Thin-Film Superconducting Nanowire Superinductors for Novel Quantum Devices

Examensarbete för masterexamen

Please use this identifier to cite or link to this item: https://hdl.handle.net/20.500.12380/204895
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Type: Examensarbete för masterexamen
Master Thesis
Title: Fabrication and Characterisation of Thin-Film Superconducting Nanowire Superinductors for Novel Quantum Devices
Authors: Niepce, David
Abstract: In this master's thesis, we present the design, fabrication and characterisation of superconducting thin-film nanowire superinductances for use in quantum information processing and quantum metrology. In order to characterise the superconducting nanowire, it is placed inside a step-impedance lambda/2 microwave resonator. In a step-impedance resonator, the strong wave impedance mismatch between the feed lines (50 ohm) and the nanowire (ca. 5 kohm) results in the formation of standing waves within the resonator. By measuring the transmission and reflection parameters of the resonator, we can probe the nanowire properties. We have shown that the high kinetic inductance of thin NbN films can be used to fabricate superinductors that exhibit an inductance two to three orders of magnitude larger than an ordinary geometric inductance of the same size. An inductance of 787 nH is demonstrated for a 200nm x 1mm nanowire. This corresponds to a reactive microwave impedance of 25 kohm at 5 GHz, which is higher than the resistance quantum h/(4e^2) = 6.5 kohm.
Keywords: Materialvetenskap;Nanovetenskap och nanoteknik;Fysik;Supraledning;Lågtemperaturfysik;Mesoskopisk fysik;Nanoteknik;Teknisk fysik;Materials Science;Nanoscience & Nanotechnology;Physical Sciences;Superconductivity;Low temperature physics;Mesoscopic physics;Nano Technology;Engineering physics
Issue Date: 2014
Publisher: Chalmers tekniska högskola / Institutionen för mikroteknologi och nanovetenskap
Chalmers University of Technology / Department of Microtechnology and Nanoscience
URI: https://hdl.handle.net/20.500.12380/204895
Collection:Examensarbeten för masterexamen // Master Theses



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