Search results for "TUNNEL"

Applications and non-idealities of submicron Al–AlOx–Nb tunnel junctions

2016

We have developed a technique to fabricate sub-micron, 0.6µm×0.6µm Al-AlOx-Nb tunnel junctions using a standard e-beam resist, angle evaporation and double oxidation of the tunneling barrier, resulting in high quality niobium, as determined by the the high measured values of the critical temperature TC ∼ 7.5 K and the gap ∆ ∼ 1.3 meV. The devices show great promise for local nanoscale thermometry in the temperature range 1 - 7.5 K. Electrical characterization of the junctions was performed at sub-Kelvin temperatures both with and without an external magnetic field, which was used to suppress superconductivity in Al and thus bring the junction into a normal-metal-insulator-superconductor (NI…

Ultrasonography and Nerve Conduction Study in patients with carpal tunnel syndrome, comparison between the two techniques before and after median ner…

2019

Abstract Purpose: Traditional evaluation of suspected carpal tunnel syndrome (CTS) involves a thorough history, physical examination, and nerve conduction velocity studies (NCS). The aim of the study is to evaluate whether ultrasound (US) is a valid alternative to the emg as a routine pre-operative examination, to evaluate patients with STC, comparing some us values with NCS findings pre and postopertively Methods: Only patients with symptoms, clinical examination, and NCS findings consistent with CTS were included in the study, according to the inclusion criteria. Four ultrasonographic variables were considered in treated patients: 1) CSPA (cross sectional pisiform area); 2) S-P dt: the la…

Development of an inductive NIS thermometer

2012

Normal metal-Insulator-Superconductor (NIS) tunnel junction thermometers have been under heavy research since 1976 after Rowell and Tsui first presented thanks to their excellent sensitivity to the temperature change in millikelvin regime. In this work, we have designed and studied an inductive readout for NIS tunnel junctions by using on-chip planar inductors and a DC SQUID (Superconducting Quantum Interference Device) to develop a sensitive and fast thermometer for studies of nanoscale heat conduction and bolometry. In this thesis, the processing of the samples fabricated in Nanoscience Center in Jyväskylä are presented, and several processing challenges have been dealt with and the fabri…

Bias and temperature dependence analysis of the tunneling current of normal metal-insulator-normal metal tunnel junctions

2003

Reducing 1/f noise in Al-AlOx-Al tunnel junctions by thermal annealing

2009

Electronic Energy Meter Based on a Tunnel Magnetoresistive Effect (TMR) Current Sensor

2017

In the present work, the design and microfabrication of a tunneling magnetoresistance (TMR) electrical current sensor is presented. After its physical and electrical characterization, a wattmeter is developed to determine the active power delivered to a load from the AC 50/60 Hz mains line. Experimental results are shown up to 1000 W of power load. A relative uncertainty of less than 1.5% with resistive load and less than 1% with capacitive load was obtained. The described application is an example of how TMR sensing technology can play a relevant role in the management and control of electrical energy.