No description available.

We consider the dynamics of Superconducting QUantum Interference Device (SQUID) rings in the presence of time dependent magnetic fields, solving the time dependent Schrodinger equation computationally. We compare the quantum mechanical behaviour of the SQUID ring with that of a simple two state system (the ammonia maser), finding close parallels between these two systems. We then consider the idea of measurement of macroscopic quantum objects by modelling the SQUID ring inductively coupled to a classical measurement device (a LC oscillator circuit). We solve the equations of motion for this coupled system both in the phenomenological Resistively Shunted Junction plus Capacitance (RSJ+C) model and within the framework of two models using a purely quantum mechanical SQUID ring.

Thesis (Master)--İzmir Institute Of Technology, İzmir, 2005. / Keywords: superconductivity, magnesium diboride, composites, superconductor. Includes bibliographical references (leaves. 56-61).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 129-132).

Thesis (M.S.)--Wisconsin. / Includes bibliographical references (leaf 131).

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1988. / Vita. Abstract. Includes bibliographical references (leaves 87-88). Also available via the Internet.

Made available in DSpace on 2014-10-09T12:41:07Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:10Z (GMT). No. of bitstreams: 1 03963.pdf: 8251824 bytes, checksum: 4ef4f7b159d4bd66a7b925fdf00235b2 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:41:07Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:10Z (GMT). No. of bitstreams: 1 03963.pdf: 8251824 bytes, checksum: 4ef4f7b159d4bd66a7b925fdf00235b2 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

The resistive and thermoelectric properties of a series of SNS sandwiches, containing different concentrations of impurity in the superconductor, have been measured. The system used for this work was In/W/In with up to 10% lead added to the indium. A technique was developed in which the interfaces were prepared by melting indium onto tungsten slices in high vacuum. The samples produced in this way were of comparable quality to those used by previous workers. The samples with pure indium were found to obey a previously developed theory for the divergent temperature dependence of the resistance just below T<SUB>c</SUB>. This theory was extended with more realistic boundary conditions and to include the proximity effect. It was then found to adequately explain the temperature dependence of the resistance over the whole range between 0.3T<SUB>c</SUB> and T<SUB>c</SUB>. The thermopower of these samples near T<SUB>c</SUB> was also found to have the temperature dependence predicted by previous theory. The results imply that the thermopower of indium changes in a discontinuous and systematic way at T<SUB>c</SUB>. This is at variance with what is expected theoretically and with previous experimental work on lead. The low temperature interface resistance was measured as a function of the concentration of lead in the indium. It was found that, for lead concentrations of up to 5%, the interface resistance was proportional to the residual resistivity of the indium as predicted by a theory of Pippard. The magnitude of this resistance was, however, not found to be in agreement with the theory. Above concentrations of 5% Pb, the low temperature resistance data was found to become irreproducible. A theory was constructed which adequately explained the temperature dependence of the resistance of the samples with up to 5% lead in the indium. The temperature dependence of the thermopower of these samples was found to be approximately as expected from theory in the region just below T<SUB>c</SUB>. However, well below T<SUB>c</SUB>, an unexplained divergence in the thermopower was found.

No description available.