Global ETD Search
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Showing 1 to 13 of 13 for “"phase slips"”.
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Probing quantum phase slips in superconducting nanowires modified using high bias voltage pulses
Quantum phase slips (QPS) or the macroscopic quantum tunneling (MQT) of a nanowire’s order parameter through an activation energy barrier have remained the subject of intense debate for many years. They are expected to occur at low enough temperature where thermally activated phase slips (TAPS) …
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Topological Excitations and Dissipation in Superconductors and Superfluids Having Multiply Connected Geometries
… via discrete topological excitations, called phase-slips, in which vortex lines cross the superconducting or superfluid channel. The interaction between these excitations in multiply connected geometries are studied in various settings. Rich consequences are found to occur, including the …
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Switching Current Distributions of Superconducting Nanowires: Evidence of Quantum Phase Slip Events
Phase slips are topological fluctuation events that carry the superconducting order-parameter field between distinct current carrying states. Owing to these phase slips low-dimensional superconductors acquire electrical resistance. In quasi-one-dimensional nanowires it is well known that at higher …
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Superconductor -Insulator Transition in Quasi-One-Dimensional Nanowires
… for Cooper pairs. Wires in the superconducting phase of the SIT are well described by the Langer-Ambegaokar-McCumber-Halperin theory of thermally activated phase slips. No resistance ""tails"" characteristic of quantum phase slips were observed. Wires in the insulating phase of the SIT follow …
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Superconductor-insulator transition in quasi-one-dimensional nanowires
… for Cooper pairs. Wires in the superconducting phase of the SIT are well described by the Langer-Ambegaokar-McCumber-Halperin theory of thermally activated phase slips. No resistance “tails” characteristic of quantum phase slips were observed. Wires in the insulating phase of the SIT follow the …
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Macroscopic quantum tunneling in superconducting nanowire devices
… the study of macroscopic quantum tunneling of phase-slips in superconducting devices, including one-dimensional nanowires, quasi-two-dimensional superconducting strips and doubly connected superconducting devices composed of two nanowires connected in parallel. We observe macroscopic quantum …
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Fabrication and measurement of superconducting nanowires
… with the theory of thermally activated phase slips. Further analysis of the voltage versus current characteristics of the wires showed behaviour not in agreement with the established theory. Various possible explanations were considered for this, with the conclusion that damage to the …
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Measurements of superconducting phase gradients by a nanowire quantum interference device templated by DNA molecules
… for the two-wire device as a function of phase gradients in the leads caused by magnetic screening currents or applied currents, and we have developed a theory to explain our observations based on an extension of the Langer- Ambegaokar-McCumber-Halperin theory of thermally activated phase …
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Resistance in Superconducting Epitaxial Niobium Nanowires
The thermally activated phase slip description of resistance in one-dimensional superconducting wires is unable to explain additional resistance observed in extremely narrow nanowires well below the critical temperature. However, attributing this additional resistance to quantum phase slips has …
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Quantum dynamics of small Josephson junctions: an application to superconductivity in granular films
… on the quantum mechanical nature of the phase difference <1> between the superconductors. In Chapters I and IT several calculations are described which focus on the junction's DC resistance. A fully quantum mechanical Hamiltonian is employed which incorporates the dissipative effects due …
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Magnetic force microscopy studies of mesoscopic superconducting structures
… (SR) of cantilever-driven thermally activated phase slips (TAPS). The SR model allows us to experimentally determine the rate of TAPS and compare it to the Langer-Ambegaokar-McCumber-Halperin (LAMH) theory for TAPS in 1D superconducting structures. Further, we use the SR model to qualitatively …
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Dissipative processes in superconducting nanodevices: nanowire-resonators, shunted nanowires, and graphene proximity junctions
… of macroscopic quantum behavior such as quantum phase slips (QPS), and the potential use of nanowires as qubits. Superconducting coplanar microwave waveguide resonators have also become a popular way of studying superconducting junctions and qubits, as they provide an extremely low noise …
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Study of ultranarrow superconducting NbN nanowires and nanowires under strong magnetic field for photon detection
… that regardless of behavior, thermal and quantum phase slips will be one of the limiting factors in producing ultra-narrow nanowire photon detectors. Until now, photon detectors have only used current biasing techniques. However, it is well known that both magnetic field and current have the …