Search for spin-polarized photoemission from GaAs using light with orbital angular momentum

Authors

• Nathan B. Clayburn, University of Nebraska - LincolnFollow
• J. L. McCarter, University of Virginia
• J. M. Dreiling, University of Nebraska - Lincoln
• M. Poelker, Thomas Jefferson National Accelerator Facility, Newport News, VA
• D. M. Ryan, University of Nebraska-Lincoln
• Timothy J. Gay, University of Nebraska - LincolnFollow

Document Type

Article

Date of this Version

2013

Citation

PHYSICAL REVIEW B 87, 035204 (2013)

DOI: 10.1103/PhysRevB.87.035204

Comments

©2013 American Physical Society. Used by permission.

Abstract

Laser light with photon energy near the band gap of GaAs and in Laguerre-Gaussian modes with different amounts of orbital angular momentum was used to produce photoemission from unstrained GaAs. The degree of electron spin polarization was measured using a micro-Mott polarimeter and found to be consistent with zero with an upper limit of ∼3% for light with up to ±5h of orbital angular momentum. In contrast, the degree of spin polarization of 32.3 ± 1.4% using circularly polarized laser light at the as the same wavelength, which is typical for bulk GaAs photocathodes.