RESONANT - BRILLOUIN - SCATTERING STUDIES OF THE A-EXCITON IN CADMIUM SULPHIDE.
Item
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Title
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RESONANT - BRILLOUIN - SCATTERING STUDIES OF THE A-EXCITON IN CADMIUM SULPHIDE.
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Identifier
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AAI8601670
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identifier
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8601670
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Creator
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LU, XING-ZE.
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Contributor
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Herman Cummins
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Date
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1985
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Language
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English
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Publisher
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City University of New York.
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Subject
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Physics, Condensed Matter
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Abstract
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High-resolution resonant-Brillouin-scattering experiments in the spectral region of the A-exciton in cadmium sulphide were performed at liquid-helium and superfluid-helium temperatures with a single-mode tunable dye laser and a Fabry-Perot interferometer followed by a double-grating spectrometer. A frequency-dependent polariton damping model was proposed to quantitatively explain the observed RBS linewidth behavior near the exciton resonance. We have given the first evidence for the k-linear interaction in the A-exciton in CdS by performing RBS experiments in a weak magnetic field. We also observed three-branch polariton behavior and measured the k-linear coefficient of the A-exciton in CdS for the first time by performing RBS experiments at superfluid-helium-temperatures. We have shown that frequency-dependent polariton damping is crucial for solving the additional boundary condition (ABC) problem from RBS intensity measurement. None of the three commonly used ABCs agree with the RBS experiments. A fit of the theoretical intensity curve calculated from a generalized ABC and the frequency-dependent damping model to the observed intensity data indicates that the dead layer effect is negligible in the A-exciton in CdS and the correct choice of ABC falls between ABC 1 and ABC 2 but close to ABC 2.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Physics
