Injection of spin polarized electrons in InAs quantum dots

AbstractWe present the results of an electrical injection study of spin polarized electrons from ferromagnetic Fe contacts into electronic shells of self-assembled InAs quantum dots (QDs) incorporated in GaAs/AlGaAs spin LED structures. The circular polarization of the emitted light was measured as function of current and magnetic field. The polarization of the EL spectra exhibits strong maxima at energies that do not coincide with the electroluminescence (EL) intensity peaks. The magnetic field dependence of the polarization maxima is consistent with spin injection from the ferromagnetic Fe contacts. The experimental results are compared with calculated emission spectra from multi-exciton complexes (N = 2 and N = 6) as function of electron spin polarization. The energies of the EL features as well as their polarization characteristics are understood in terms of energy shifts due to exchange interactions between spin-down electrons occupying adjacent shells.

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Nuclear spin polarization by out-of-plane spin injection from ferromagnet into an InAs heterostructure

MRS Proceedings ◽

10.1557/opl.2012.879 ◽

2012 ◽

Vol 1396 ◽

Author(s):

Tomotsugu Ishikura ◽

Takahiro Hiraki ◽

Takashi Matsuda ◽

Joungeob Lee ◽

Kanji Yoh

Keyword(s):

Magnetic Field ◽

Spin Polarization ◽

Nuclear Spin ◽

Spin Injection ◽

Hall Voltage ◽

Nuclear Spin Polarization ◽

Polarized Electrons ◽

Spin Polarized ◽

Magnetic Metal ◽

Out Of Plane

AbstractWe have investigated an InAs channel Hall-bar structure with ferromagnetic spin injector in one of the current terminals. After magnetizing the Fe electrode, spin polarized electrons are injected through the edge of the isolation mesa structure and the anomalous Hall voltage is observed, when electrons are injected from the ferromagnetic terminal. However, when electrons are injected from the non-magnetic metal (Ti/Au) of opposite terminal, the Hall voltage disappeared to the variation error level due to the fabrication imperfections. This result suggests the possibility that out-of-plane spin injection from the channel edge lead to perpendicular nuclear magnetic field. It is presumably caused by nuclear spin polarization in InAs channel near the spin source edge through Overhauser effect. The estimated internal magnetic field was 2000 Gauss.

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Electron spin polarization and detection in InAs quantum dots throughp-shell trions

Physical Review B ◽

10.1103/physrevb.81.045305 ◽

2010 ◽

Vol 81 (4) ◽

Cited By ~ 10

Author(s):

S. G. Carter ◽

Ş. C. Bădescu ◽

A. S. Bracker

Keyword(s):

Quantum Dots ◽

Spin Polarization ◽

Electron Spin ◽

Electron Spin Polarization ◽

Inas Quantum Dots

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Spin-polarization effects in Cherenkov radiation from electrons

Canadian Journal of Physics ◽

10.1139/cjp-2019-0441 ◽

2020 ◽

Vol 98 (7) ◽

pp. 660-663

Author(s):

A.A. Peshkov

Keyword(s):

Spin Polarization ◽

Cherenkov Radiation ◽

Stokes Parameters ◽

Electron Spin Polarization ◽

Polarized Electrons ◽

Small Component ◽

Polarization Effects ◽

Spin Polarized ◽

Linearly Polarized ◽

Spin Polarization Effects

A quantum electrodynamical theory of Cherenkov radiation emitted by spin-polarized electrons moving in an isotropic medium is developed within the density matrix framework. Special attention is paid to the polarization properties of the emitted photons described by means of Stokes parameters. It is demonstrated that, although the Cherenkov radiation is primarily linearly polarized in the plane containing the direction of observation and the path of the electrons, the photons may have a small component of circular polarization of the order of 3 × 10−6 for electron kinetic energy of 500 keV due to the initial electron spin polarization, whose existence can be confirmed by sensitive measurements in the future.

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Asymmetric reactions induced by electron spin polarization

Physical Chemistry Chemical Physics ◽

10.1039/d0cp03129a ◽

2020 ◽

Vol 22 (38) ◽

pp. 21570-21582 ◽

Cited By ~ 3

Author(s):

B. P. Bloom ◽

Y. Lu ◽

Tzuriel Metzger ◽

Shira Yochelis ◽

Yossi Paltiel ◽

...

Keyword(s):

Spin Polarization ◽

Electron Spin ◽

Asymmetric Reactions ◽

Electron Spin Polarization ◽

Electrochemical Reactions ◽

Polarized Electrons ◽

Spin Polarized

Spin polarized electrons can control asymmetric electrochemical reactions.

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Magnetotransport Properties in a Lateral Spin-Injection Device with a Ferromagnetic/Si/ Ferromagnetic Junction

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.1081 ◽

2004 ◽

Vol 449-452 ◽

pp. 1081-1084

Author(s):

Woong Joon Hwang ◽

H.J. Lee ◽

K.I. Lee ◽

J.M. Lee ◽

J.Y. Chang ◽

...

Keyword(s):

Magnetic Fields ◽

Spin Transport ◽

Spin Injection ◽

The Other ◽

Injection Device ◽

Polarized Electrons ◽

Spin Polarized ◽

First Contact

The spin transport in a lateral spin-injection device with an FeCo/Si/FeCo junction has been investigated. Magnetoresistance (MR) signals were found to appear at low magnetic fields in the range 4 300 K. This is attributable to the switching of the magnetization of the two ferromagnetic contacts in the device for certain magnetic fields over which the magnetization in one contact is aligned antiparallel to that in the other. Our results suggest that the spin-polarized electrons are injected from the first contact and, after propagating through the bulk Si, are collected by the second contact.

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Photoluminescence spectroscopy of self-assembled InAs quantum dots in strong magnetic field and under high pressure

Applied Physics Letters ◽

10.1063/1.118194 ◽

1997 ◽

Vol 70 (4) ◽

pp. 505-507 ◽

Cited By ~ 61

Author(s):

I. E. Itskevich ◽

M. Henini ◽

H. A. Carmona ◽

L. Eaves ◽

P. C. Main ◽

...

Keyword(s):

Magnetic Field ◽

Quantum Dots ◽

High Pressure ◽

Strong Magnetic Field ◽

Photoluminescence Spectroscopy ◽

Inas Quantum Dots ◽

Self Assembled

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Magnetic-field-induced singularities in spin-dependent tunneling through InAs quantum dots

Physical Review B ◽

10.1103/physrevb.62.12621 ◽

2000 ◽

Vol 62 (19) ◽

pp. 12621-12624 ◽

Cited By ~ 58

Author(s):

I. Hapke-Wurst ◽

U. Zeitler ◽

H. Frahm ◽

A. G. M. Jansen ◽

R. J. Haug ◽

...

Keyword(s):

Magnetic Field ◽

Quantum Dots ◽

Inas Quantum Dots

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Tunnelling in a magnetic field with spin-polarized electrons

Physica Scripta ◽

10.1088/0031-8949/38/2/032 ◽

1988 ◽

Vol 38 (2) ◽

pp. 272-276 ◽

Cited By ~ 18

Author(s):

R Meservey

Keyword(s):

Magnetic Field ◽

Polarized Electrons ◽

Spin Polarized

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Optical Pumping and Optical Detection of Spin-Polarized Electrons in a Conduction Band

Canadian Journal of Physics ◽

10.1139/p71-222 ◽

1971 ◽

Vol 49 (14) ◽

pp. 1850-1860 ◽

Cited By ~ 33

Author(s):

R. R. Parsons

Keyword(s):

Magnetic Field ◽

Conduction Band ◽

Spin Polarization ◽

Optical Pumping ◽

Polarized Light ◽

Degree Of Polarization ◽

Polarized Electrons ◽

Excitation Light ◽

Circularly Polarized Light ◽

Spin Polarized

Spin-polarized electrons are created in the conduction band of p-type GaSb by excitation with σ+ or σ− circularly polarized light. The degree of polarization of the photoluminescence is used to measure the optically pumped spin polarization. The measurements as a function of transverse magnetic field yield the spin-relaxation time and the lifetime of the photocreated electrons. The degree of polarization oscillates as a function of the photon energy of the excitation light. This effect is associated with mechanisms of rapid energy loss involving optical and acoustical phonons. The optical pumping is studied as a function of temperature in the range 3.5 °K ≤ T ≤ 11 °K. A maximum spin polarization [Formula: see text] is obtained at [Formula: see text]. The efficiency of the optical pumping is significantly increased with the application of a weak longitudinal magnetic field.

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