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Title: A comprehensive evaluation of factors that influence the spin polarization of electrons emitted from bulk GaAs photocathodes

Here, the degree of polarization of photoemitted electrons extracted from bulk unstrained GaAs photocathodes is usually considerably less than the theoretical maximum value of 50%, as a result of depolarization mechanisms that originate within the photocathode material and at the vacuum surface interface. This paper provides a comprehensive review of depolarization mechanisms and presents a systematic experimental evaluation of polarization sensitivities to temperature, dopant density, quantum efficiency, and crystal orientation. The highest measured polarization was similar to 50%, consistent with the maximum theoretical value, obtained from a photocathode sample with relatively low dopant concentration and cooled to 77 K. In general, measurements indicate electron spin polarization can be enhanced at the expense of photoelectron yield (or quantum efficiency).
Authors:
 [1] ;  [2] ;  [3] ; ORCiD logo [2] ;  [2]
  1. Chinese Academy of Sciences, Lanzhou (China); Univ. of Chinese Academy of Sciences, Beijing (China); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  2. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  3. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); East China Institute of Technology, Nanchang (China)
Publication Date:
Report Number(s):
JLAB-ACC-17-2443; DOE/OR/23177-4112
Journal ID: ISSN 0021-8979
Grant/Contract Number:
AC05-06OR23177
Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 122; Journal Issue: 3; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Research Org:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1375337
Alternate Identifier(s):
OSTI ID: 1371797

Liu, Wei, Poelker, Matt, Peng, Xincun, Zhang, Shukui, and Stutzman, Marcy. A comprehensive evaluation of factors that influence the spin polarization of electrons emitted from bulk GaAs photocathodes. United States: N. p., Web. doi:10.1063/1.4994306.
Liu, Wei, Poelker, Matt, Peng, Xincun, Zhang, Shukui, & Stutzman, Marcy. A comprehensive evaluation of factors that influence the spin polarization of electrons emitted from bulk GaAs photocathodes. United States. doi:10.1063/1.4994306.
Liu, Wei, Poelker, Matt, Peng, Xincun, Zhang, Shukui, and Stutzman, Marcy. 2017. "A comprehensive evaluation of factors that influence the spin polarization of electrons emitted from bulk GaAs photocathodes". United States. doi:10.1063/1.4994306. https://www.osti.gov/servlets/purl/1375337.
@article{osti_1375337,
title = {A comprehensive evaluation of factors that influence the spin polarization of electrons emitted from bulk GaAs photocathodes},
author = {Liu, Wei and Poelker, Matt and Peng, Xincun and Zhang, Shukui and Stutzman, Marcy},
abstractNote = {Here, the degree of polarization of photoemitted electrons extracted from bulk unstrained GaAs photocathodes is usually considerably less than the theoretical maximum value of 50%, as a result of depolarization mechanisms that originate within the photocathode material and at the vacuum surface interface. This paper provides a comprehensive review of depolarization mechanisms and presents a systematic experimental evaluation of polarization sensitivities to temperature, dopant density, quantum efficiency, and crystal orientation. The highest measured polarization was similar to 50%, consistent with the maximum theoretical value, obtained from a photocathode sample with relatively low dopant concentration and cooled to 77 K. In general, measurements indicate electron spin polarization can be enhanced at the expense of photoelectron yield (or quantum efficiency).},
doi = {10.1063/1.4994306},
journal = {Journal of Applied Physics},
number = 3,
volume = 122,
place = {United States},
year = {2017},
month = {7}
}