Trion-based Optical Processes in Semiconductor Quantum Wells

dc.contributor.advisorSteck, Daniel
dc.contributor.authorBaldwin, Thomas
dc.date.accessioned2016-02-24T00:33:50Z
dc.date.available2016-02-24T00:33:50Z
dc.date.issued2016-02-23
dc.description.abstractIn a semiconductor, negative charge is carried by conduction-band electrons and positive charge is carried by valence-band holes. While charge transport properties can be understood by considering the motion of these carriers individually, the optical properties are largely determined by their mutual interaction. The hydrogen-like bound state of an electron with a hole, or exciton, is the fundamental optical excitation in direct-gap materials such as gallium arsenide and cadmium telluride. In this dissertation, we consider charged excitons, or trions. A bound state of an exciton with a resident electron or hole, trions are a relatively pure manifestation of the three-body problem which can be studied experimentally. This is a subject of practical as well as academic interest: Since the trion is the elementary optical excitation of a resident free carrier, the related optical processes can open pathways for manipulating carrier spin and carrier transport. We present three experimental investigations of trion-based optical processes in semiconductor quantum wells. In the first, we demonstrate electromagnetically induced transparency via the electron spin coherence made possible by the trion transition. We explore the practical limits of this technique in high magnetic fields. In the second, we present a direct measurement of trion and exciton oscillator strength at high magnetic fields. These data reveal insights about the structure of the trion's three-body wavefunction relative to that of its next excited state, the triplet trion. In the last, we investigate the mechanism underlying exciton-correlated tunneling, an optically-controllable transport process in mixed-type quantum wells. Extensive experimental studies indicate that it is due to a local, indirect interaction between an exciton and a hole, forming one more example of a trion-mediated optical process. This dissertation includes previously published co-authored material.en_US
dc.identifier.urihttps://hdl.handle.net/1794/19728
dc.language.isoen_US
dc.publisherUniversity of Oregon
dc.rightsAll Rights Reserved.
dc.subjectExcitonsen_US
dc.subjectGallium arsenideen_US
dc.subjectQuantum wellsen_US
dc.subjectTrionsen_US
dc.titleTrion-based Optical Processes in Semiconductor Quantum Wells
dc.typeElectronic Thesis or Dissertation
thesis.degree.disciplineDepartment of Physics
thesis.degree.grantorUniversity of Oregon
thesis.degree.leveldoctoral
thesis.degree.namePh.D.

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