TY - JOUR

T1 - Spectral detection of spin-polarized ultra low-energy electrons in semiconductor heterostructures

AU - Golyashov, V. A.

AU - Rusetsky, V. S.

AU - Shamirzaev, T. S.

AU - Dmitriev, D. V.

AU - Kislykh, N. V.

AU - Mironov, A. V.

AU - Aksenov, V. V.

AU - Tereshchenko, O. E.

N1 - Copyright © 2020 Elsevier B.V. All rights reserved.

PY - 2020/11/1

Y1 - 2020/11/1

N2 - The circularly polarized cathodoluminescence (CL) technique has been used to study the free spin-polarized electron injection in semiconductor heterostructures with quantum wells (QWs). A polarized electron beam was created by the emission of optically oriented electrons from the p-GaAs(Cs,O) negative electron affinity (NEA) photocathode. The prepared beam was injected in a semiconductor QW target, which was activated by cesium and oxygen to reduce the work function. To study the spin-dependent injection, we developed a spin-detector prototype, which consists of a compact proximity focused vacuum tube with the source and target placed parallel to each other on the opposite ends of the vacuum tube (photodiode). The injection of polarized low-energy electrons into the target by varying the kinetic energy in the range of 0.5-5.0 eV and temperature in the range of 90-300 K was studied. The CL was polarized to 2 % by the injection of 20 % spin-polarized electron beam with the energy of 0.5 eV at room temperature. The asymmetry (Sherman function) of spin detection was estimated. It was shown that the dependence of the CL polarization degree on the injected electron energy is satisfactory described by the model that considers the electron spin relaxation in the heterostructure matrix and QWs. The results demonstrate that semiconductor detectors are promising for the spin-polarimetry applications based on the optical detection of free-electron spin polarization.

AB - The circularly polarized cathodoluminescence (CL) technique has been used to study the free spin-polarized electron injection in semiconductor heterostructures with quantum wells (QWs). A polarized electron beam was created by the emission of optically oriented electrons from the p-GaAs(Cs,O) negative electron affinity (NEA) photocathode. The prepared beam was injected in a semiconductor QW target, which was activated by cesium and oxygen to reduce the work function. To study the spin-dependent injection, we developed a spin-detector prototype, which consists of a compact proximity focused vacuum tube with the source and target placed parallel to each other on the opposite ends of the vacuum tube (photodiode). The injection of polarized low-energy electrons into the target by varying the kinetic energy in the range of 0.5-5.0 eV and temperature in the range of 90-300 K was studied. The CL was polarized to 2 % by the injection of 20 % spin-polarized electron beam with the energy of 0.5 eV at room temperature. The asymmetry (Sherman function) of spin detection was estimated. It was shown that the dependence of the CL polarization degree on the injected electron energy is satisfactory described by the model that considers the electron spin relaxation in the heterostructure matrix and QWs. The results demonstrate that semiconductor detectors are promising for the spin-polarimetry applications based on the optical detection of free-electron spin polarization.

KW - Angle-resolved photoemission spectroscopy

KW - Circularly polarized cathodoluminescence

KW - Electron spin polarization

KW - Negative electron affinity

KW - Spin-detector

KW - DEPENDENT TRANSMISSION

KW - GAAS

UR - http://www.scopus.com/inward/record.url?scp=85088844518&partnerID=8YFLogxK

U2 - 10.1016/j.ultramic.2020.113076

DO - 10.1016/j.ultramic.2020.113076

M3 - Article

C2 - 32738565

AN - SCOPUS:85088844518

VL - 218

JO - Ultramicroscopy

JF - Ultramicroscopy

SN - 0304-3991

M1 - 113076

ER -