Strain enhanced electron spin polarization observed in photoemision from InGaAs

Conference · Wed May 01 04:00:00 EDT 1991

OSTI ID:5843183

Maruyama, T; Garwin, E L ^[1]; Prepost, R; Zapalac, G H ^[2]; Smith, J S; Walker, J D ^[3]

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1. Stanford Linear Accelerator Center, Menlo Park, CA (USA)
2. Wisconsin Univ., Madison, WI (USA). Dept. of Physics
3. California Univ., Berkeley, CA (USA)

Electron spin polarization in excess of 70% has been observed in photoemission from a 0.1 {mu}m-thick epitaxial layer of In{sub x}Ga{sub 1-x}As with x {approx} 0.13 grown on a GaAs substrate. Under these conditions, the epitaxial layer is expected to be highly strained by the 0.9% lattice mismatch, as confirmed by X-ray diffractometer measurements of the lattice parameter. The electron polarization and the quantum efficiency have been measured as a function of the excitation photon energy from 1.25 to 2.0 eV. A significant enhancement of the electron polarization occurs in the vicinity of 1.33 eV where the expected strain-induced level splitting permits optical excitation of a single band transition. Measurements made on a control sample of 1.14 {mu}m thickness, significantly larger than the critical thickness for pseudomorphic strain, show no polarization enhancement. These measurements represent the first observation of strain-enhanced electron spin polarization for photoemitted electrons. 7 refs., 3 figs.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (USA)
• Sponsoring Organization: DOE; NSF; USDOE, Washington, DC (USA); National Science Foundation, Washington, DC (USA)
• DOE Contract Number: AC03-76SF00515; AC02-76ER00881
• OSTI ID: 5843183
• Report Number(s): SLAC-PUB-5546; CONF-910505--84; WISC-ex--91-317; ON: DE91012319; CNN: NSF-87-11709
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430301* -- Particle Accelerators-- Ion Sources
656002 -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACCELERATORS
ARSENIC COMPOUNDS
ARSENIDES
CATHODES
ELECTRODES
ELECTRON SOURCES
EMISSION
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
LINEAR ACCELERATORS
ORIENTATION
PARTICLE SOURCES
PHOTOCATHODES
PHOTOEMISSION
PNICTIDES
RADIATION SOURCES
SECONDARY EMISSION
SPIN ORIENTATION