Quantum interference effects in HgCdTe MISFETS /
| Main Author: | |
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | Quantum interference effects have been studied in Hg[0.78]Cd[0.22]Te metal-insulator-semiconductor field effect transistors (MISFETs) at low temperatures 20 mK < T < 4 K. The low effective mass (m* = 0.006m[0], in bulk Hg[0.78]Cd[0.22]Te and strong spin-orbit scattering in these devices make them a unique system in which to probe quantum interference effects. These interference effects, weak localization, and universal conductance fluctuations, were probed by measuring the magnetoresistance at low temperatures with a four-probe dc resistance technique. By fitting weak localization theory to the data, the elastic scattering time, the dephasing scattering time, and the spin-orbit scattering time were derived. These characteristic scattering times have revealed new information about the electronic transport within these devices at low temperatures. In addition, because the sizes of these devices were somewhat larger than the dephasing length, weak localization effects and universal conductance fluctuations were simultaneously observable in the same device. This made the quantitative comparison of weak localization effects and universal conductance fluctuations possible, and resulted in the most accurate confirmation of universal conductance fluctuation theory to date. Furthermore, the component of the conductance fluctuations antisymmetric with respect to the current, was found to be inversely proportional to the source-drain voltage across the device. This was interpreted as being due to voltage fluctuations which were independent of the direction of the current. The voltage fluctuations were explained by a model which predicted oscillations in the chemical potential, due to local interference of the electron wave at scattering centers. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Physics." |
| Physical Description: | xi, 171 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |