Magneto-Optical Properties of Narrow Gap Semiconductor Nanostructures

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Material Information

Title:
Magneto-Optical Properties of Narrow Gap Semiconductor Nanostructures
Physical Description:
1 online resource (123 p.)
Language:
english
Creator:
Saha, Dipta
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Physics
Committee Chair:
STANTON,CHRISTOPHER JAY
Committee Co-Chair:
DUFTY,JAMES W
Committee Members:
MUTTALIB,KHANDKER A
TANNER,DAVID B
BOWERS,CLIFFORD RUSSELL

Subjects

Subjects / Keywords:
opnmr -- optical -- photonics -- polarization -- properties -- spin -- spintronics
Physics -- Dissertations, Academic -- UF
Genre:
Physics thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
I have theoretically studied different experiments for a range of III-V nanostructures including: (1) time resolved differential transmission (TRDT) spectra in ferromagnetic InMnAs without magnetic field, (2) cyclotron resonance (CR) in ferromagnetic InMnAs and InMnSb, (3) optically pumped NMR (OPNMR) in strained AlGaAs/GaAs square multi quantum wells (MQW) and (4) magneto-absorption in strained AlInSb/InSb parabolic MQW. The calculations and modeling have helped explain interesting phenomena: 1) carrier relaxation and dynamics, 2) sign changes in the TRDT spectra, 3) higher Curie temperature of the MOVPE grown ferromagnetic samples, 4) the sensitivity and sign of the OPNMR signal, and 5) the effects of strain and confinement on the magneto-absorption. I have used an 8-band model modified to include sp-d coupling between electrons and holes and Mn impurities to calculate the band structure of the ferromagnetic InMnAs. To calculate the Landau subband structure for the other materials, I have used the 8-band modified Pidgeon Brown model. Fermi's golden rule is used to calculate the optical properties. The band structure calculations, along with the identification of the optical transitions, explain the carrier dynamics and relaxation mechanisms and the sign changes in the TRDT spectra as a function of probe wavelength. The calculations of CR spectra, valence Landau suband structure, and average z component of the spins explain the differences between the CR measurements that are observed in molecular beam epitaxy (MBE) and metal organic vapor phase epitaxy (MOVPE) samples, and the higher Curie temperature in the MOVPE structures. In the OPNMR experiments on AlGaAs/GaAs MQW, the sign change of the calculated electron spin polarization agrees with the sign change of the OPNMR signal. This sign change has not been observed in bulk GaAs. The strain effect and density of states in the strained MQW are responsible for this sign change. The calculated magneto-absorption with biaxial strain effects included more accurately reproduces the experimental results of AlInSb/InSb parabolic MQW. Comparing the results with that of the AlInSb/InSb square MQW indicates that the shape of the confinement affects the magneto-absorption significantly.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Dipta Saha.
Thesis:
Thesis (Ph.D.)--University of Florida, 2014.
Local:
Adviser: STANTON,CHRISTOPHER JAY.
Local:
Co-adviser: DUFTY,JAMES W.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2016-05-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2014
System ID:
UFE0046468:00001