Title | A Comprehensive Evaluation of Factors that Influence the Spin Polarization of Electrons Emitted from Bulk GaAs Photocathodes |
Authors | Wei Liu, M. Poelker, Xincun Peng, Shukui Zhang, Marcy Stutzman |
JLAB number | JLAB-ACC-17-2443 |
LANL number | (None) |
Other number | DOE/OR/23177-4112 |
Document Type(s) | (Journal Article) |
Associated with EIC: | No |
Supported by Jefferson Lab LDRD Funding: | No |
Funding Source: | Nuclear Physics (NP) |
Citation (AIP): |
W. Liu, M. Poelker, X. Peng, S. Zhang and M. Stutzman, J.Appl.Phys. 122, 035703 (2017). |
Publication Abstract: | 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 ~ 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, QE). |
Experiment Numbers: | other |
Group: | Ctr for Injectors&Sources |
Document: | pdf |
DOI: | http://dx.doi.org/10.1063/1.4994306 |
Accepted Manuscript: | JR17-1209_revision.pdf embargoed final, peer reviewed, accepted manuscript |
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