Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 19 of 19 for “"persistent current"”.
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Large amplitude driving of a persistent current qubit
In this thesis, the persistent current qubit in the presence of large amplitude microwave radiation is studied. Three main results are presented in this work. A new coherent quasi classical regime has been observed, where coherent quantum dynamics persist even while transitions between energy …
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Resonant readout of a superconducting persistent current qubit
… resonant readout scheme developed for a niobium persistent-current (PC) qubit. This non-dissipative readout approach detects the flux state of the qubit by sensing a change in the Josephson inductance of a SQUID magnetometer. By incorporating the SQUID inductor in a high-Q resonant circuit, we …
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Fabrication and measurement of a niobium persistent current qubit
… device proposed as a quantum bit--the Persistent Current (PC) qubit. The thesis discusses the fabrication of niobium Josephson junction devices which is integral to the design and measurement of the circuit. The devices were fabricated at MIT Lincoln Laboratory using optical projection …
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Measurement and on-chip control of a niobium persistent current qubit
The persistent current qubit is a superconducting ring interrupted by three Josephson junctions. Its two quantum states have circulating currents in opposite directions which can be measured by a dc SQUID magnetometer. This work examines a persistent current qubit fabricated in niobium, using …
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On the Typical and Average Contributions to the Persistent Current in Mesoscopic Rings
… result: the presence of equilibrium <i>persistent</i> currents, with nanoampere-sized amplitudes and either <i>h/e</i>- or <i>h/2e</i>-periodicity in the applied magnetic flux. This effect follows from the extended phase coherence of the conduction electrons in this disordered mesoscopic …
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Effects of dissipative environments on some quantum systems
… on the following physical phenomena: the persistent current of a metallic ring, the escape rate of an electron from a helium surface, and the transition probability of the Landau-Zener level crossing. Chapter one contains a general introduction to these physical systems and a brief review …
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Effects of dissipative environments on some quantum systems
… on the following physical phenomena: the persistent current of a metallic ring, the escape rate of an electron from a helium surface, and the transition probability of the Landau-Zener level crossing.
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External Imbalances and the Valuation Channel
… account has been partially used to finance the persistent current account deficit, which has given rise to a large negative net international financial position. The current practice for calculating the size of the financial account is to net off the size of the foreign assets and foreign …
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Critical temperatures of superconducting solders
… able to gather more useful data. Replacing the persistent-current switch (PCS), which needs to be warmed beyond its critical temperature at times in order to charge or discharge the magnet, with a mechanical switch that can be kept at its superconducting stage may be able to speed up the …
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Coherence characterization with a superconducting flux qubit through NMR approaches
… the coherence properties of a superconducting persistent-current or flux qubit, a promising candidate for developing a scalable quantum processor. A collection of coherence characterization experiments and techniques that originate from the field of nuclear magnetic resonance (NMR) are …
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Flow of Entropy in Equilibrium and Non-Equilibrium Quantum Systems
… converse, in a range of systems that define the current and coming technological revolution, those of open quantum systems in and out of equilibrium. Simple and comprehensible formulas for global and local heat and entropy currents are proposed and interpreted through the use of Non-Equilibrium …
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Thermal activation of superconducting Josephson junctions
… quantum interference devices (SQUIDs) and in persistent-current qubit systems. Noise excitations, however, have a critical influence on their dynamics. Thus, the primary focus of this research was to investigate the effects of thermal activation on the superconducting properties of Josephson …
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Voltage-Gated Sodium Channel Activity in Mouse Skeletal Muscle Fibers: Normal Gating and Defects Associated with Periodic Paralysis Mutants
… clamp protocol to improve the fidelity of Na+ current recording from acutely dissociated intact muscle fibers. Computer simulation, incorporating measured capacitance and ionic current densities, was used to confirm sufficient voltage control and distortion-free Na+ currents. The gating …
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Essays on current account dynamics and fiscal rules in sub-Saharan Africa
Large and persistent current account and fiscal deficits coexisting alongside high public debt levels pose significant risks to macroeconomic stability and limit policymaking options. This thesis focuses on the current account dynamics and fiscal policy in the sub-Saharan Africa region. Over the …
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Stacks of high temperature superconducting tape as trapped field magnets for energy applications
… where the field is generated by a circulating persistent current in the sample, can create magnetic fields an order of magnitude higher than possible using conventional ferromagnets, thus increasing the power density of motors and generators. This is of great interest where added weight comes …
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An investigation into a flux-pumped high-temperature superconducting MRI system
… magnets, fusion magnets, superconducting fault current limiters, energy storage devices, and many others. Among all of the applications, MRI magnets make up the major part of the commercial application of superconductors. More than 80 % of MRI scanners around the world use superconducting …
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Current account deficits and sustainability: evidence from South Africa
This paper investigates current account sustainability in South Africa using stationarity and coin tegration approaches to assessing intertemporal solvency - where intertemporal solvency implies current account sustainability. The contribution in this paper are four-fold. First, we consider a key …
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A persistent-mode MgB₂ 0.5-T/240-mm solid-nitrogen-cooled magnet for MRI
… superconductors carry more than 100 times higher current density than copper, while generating no Joule heat, they are the only practical choice for diagnostic MRI magnets with field strengths above 1 T. A low-temperature superconductor of niobium titanium (NbTi) with a critical temperature of 9.8 …
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Electromagnetic-thermal Characteristics of Conductor on Round Core (CORC) Cables
… as coated conductors (HTS-CCs), showing high current density in a high magnetic field, are already commercially available. As a cabling concept, Conductor on Round Core (CORC) cables consisting of a cylindrical former and multiple helically bent HTS-CCs, exhibit more significant …