Showing papers by "Tim Duty published in 2022"
TL;DR: In this paper , weakly nonlinear kinetic inductance intrinsic to a superconducting film of niobium titanium nitride was used to construct a microwave parametric amplifier with high phase-sensitive gain and high power handling.
Abstract: Microwave parametric amplifiers operating at the quantum noise limit have become indispensable tools for a range of cryogenic quantum technologies. These amplifiers are typically constructed from nonlinear Josephson junctions, which limit the ability to amplify high-power signals. This study reports a device based instead on the weakly nonlinear kinetic inductance intrinsic to a superconducting film of niobium titanium nitride. The amplifier offers large phase-sensitive gain and high power handling, plus a simple design and fabrication process. As it contains no junctions, it is robust to electrostatic discharge and potentially operable under high temperatures and large magnetic fields.
17 citations
12 Jul 2022
TL;DR: In this article , the formation of superconductivity in nanowires fabricated with silicon-on-insulator (SOI) was investigated, and the phase transformed material is conformal with any predefined device patterns and the resultant structures are exceptionally smooth-walled compared to similar nanowire devices formed by silicidation processes.
Abstract: The development of a materials platform that exhibits both superconducting and semiconducting properties is an important endeavour for a range of emerging quantum technologies. We investigate the formation of superconductivity in nanowires fabricated with silicon-on-insulator (SOI). Aluminium from deposited contact electrodes is found to interdiffuses with the Si nanowire structures to form an Al-Si alloy along the entire length of the predefined nanowire device over micron length scales at temperatures well below that of the Al-Si eutectic. The resultant transformed nanowire structures are layered in geometry with a continuous Al-Si alloy wire sitting on the buried oxide of the SOI and a residual Si cap sitting on top of the wire. The phase transformed material is conformal with any predefined device patterns and the resultant structures are exceptionally smooth-walled compared to similar nanowire devices formed by silicidation processes. The superconducting properties of a mesoscopic AlSi ring formed on a SOI platform are investigated. Low temperature magnetoresistance oscillations, quantized in units of the fluxoid, h/ 2 e , are observed.
TL;DR: In this paper , the superconducting properties of a transformed mesoscopic ring formed on a silicon-on-insulator (SOI) platform are investigated, and low-temperature magnetoresistance oscillations, quantized in units of the fluxoid, h/2e are observed.
Abstract: The development of devices that exhibit both superconducting and semiconducting properties is an important endeavor for emerging quantum technologies. We investigate superconducting nanowires fabricated on a silicon-on-insulator (SOI) platform. Aluminum from deposited contact electrodes is found to interdiffuse with Si along the entire length of the nanowire, over micrometer length scales and at temperatures well below the Al-Si eutectic. The phase-transformed material is conformal with the predefined device patterns. The superconducting properties of a transformed mesoscopic ring formed on a SOI platform are investigated. Low-temperature magnetoresistance oscillations, quantized in units of the fluxoid, h/2e, are observed.