scholarly journals Scanning-Ion Microscopy with Polarization Analysis (Simpa)

1993 ◽  
Vol 313 ◽  
Author(s):  
N. J. Zheng ◽  
C. Rau
Keyword(s):  
High Resolution ◽  
Spin Polarization ◽  
Imaging Technique ◽  
Ion Beam ◽  
Polarization Analysis ◽  
Polarized Electrons ◽  
Magnetic Structures ◽  
Magnetic Imaging ◽  
Spin Polarized ◽  
Ion Microscopy

ABSTRACTWe have developed a novel, high-resolution magnetic imaging technique, scanning-ion microscopy with polarization analysis (SIMPA). In SIMPA, a highly-focused, scanning Ga+ ion beam is used to excite spin-polarized electrons at surfaces of ferromagnetic Materials. By Measuring the intensity and the spin polarization of the emitted electrons using a newly developed, compact mott polarimeter, topographic and magnetic images of magnetic structures are obtained. We report on first SIMPA studies on single-crystalline Fe samples.

Spin-polarization effects in Cherenkov radiation from electrons

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.

Spin-Polarized Scanning Tunneling Microscopy (SPSTM)

1991 ◽  
Vol 231 ◽  
Author(s):  
R. Wiesendanger ◽  
D. Buergler ◽  
G. Tarrach ◽  
I.V. Shvets ◽  
H.-J. Guentherodt
Keyword(s):  
Scanning Tunneling Microscope ◽  
High Spatial Resolution ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Promising Technique ◽  
Polarized Electrons ◽  
Tunneling Microscope ◽  
Magnetic Structures ◽  
Spin Polarized

AbstractWe report on a novel promising technique for the investigation of magnetic structures at surfaces at high spatial resolution, ultimately down to the atomic scale. This technique is based on the observation of vacuum tunneling of spin-polarized electrons by means of a scanning tunneling microscope (STM). We discuss appropriate probe tips for the spin-polarized STM (SPSTM) and describe initial experimental results. We further focus on the information obtained by SPSTM. Finally, the perspectives of SPSTM will be discussed.

Asymmetric reactions induced by electron spin polarization

2020 ◽  
Vol 22 (38) ◽  
pp. 21570-21582 ◽  
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.

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

1971 ◽  
Vol 49 (14) ◽  
pp. 1850-1860 ◽  
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.

scholarly journals Spin Manipulation in Co-Doped ZnO

2010 ◽  
Vol 67 ◽  
pp. 192-197 ◽  
Author(s):  
Heidemarie Schmidt
Keyword(s):  
Spin Polarization ◽  
Electron Concentration ◽  
Schottky Diodes ◽  
Weak Localization ◽  
Spin Splitting ◽  
Zno Films ◽  
Polarized Electrons ◽  
Spin Polarized ◽  
Doped Zno ◽  
Co Doped

The magnetoresistance of n-type conducting, paramagnetic Co-doped ZnO films prepared by pulsed laser deposition on sapphire substrates has been studied experimentally and theoretically. Positive magnetoresistance (MR) of 124% has been observed in the film with the lowest electron concentration of 8.3·1017 cm−3, while only a negative MR of −1.9% was observed in the film with an electron concentration of 9.9·1019 cm−3 at 5 K. The positive MR is attributed to the quantum correction on the conductivity due to the <em>s</em>-<em>d </em>exchange interaction induced spin splitting of the conduction band. The negative MR is attributed to the magnetic field suppressed weak localization [1]. Voltage control of the electron concentration in Schottky diodes revealed a drastic change of the magnetoresistance and demonstrated the electrically controllable magnetotransport behavior in Co-doped ZnO [2]. The magnetically controllable spin polarization in Co-doped ZnO has been demonstrated at 5 K in magnetic tunnel junctions with Co-doped ZnO as a bottom electrode and Co as a top electrode [3]. There spin-polarized electrons were injected from Co-doped ZnO to a crystallized Al2O3 layer and tunnelled through an amorphous Al2O3 barrier. Our studies demonstrate the spin polarization and manipulation in Co-doped ZnO.

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

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.

SPIN POLARIZATION OF ELECTRONS BY DEPOSITING HYBRID FERROMAGNETIC STRIPES ON A SEMICONDUCTOR HETEROSTRUCTURE

2004 ◽  
Vol 11 (03) ◽  
pp. 331-335 ◽  
Author(s):  
MAO-WANG LU
Keyword(s):  
Spin Polarization ◽  
Practical Importance ◽  
Magnetic Nanostructures ◽  
Polarized Electrons ◽  
Semiconductor Heterostructure ◽  
Alternative Approach ◽  
Spin Polarized ◽  
Spin Polarization Effect ◽  
Magnetic Barriers ◽  
Two Hybrid

One type of combined magnetically modulated nanostructures is proposed that can be experimentally realized by depositing two hybrid ferromagnetic stripes on the surface of a semiconductor heterostructure. Since these two stripes induce different magnetic barriers, the electron transmission and the conductance of nanostructure are strongly dependent upon the electronic spins. Thus, in this kind of hybrid magnetic nanostructures, electrons show up a considerable spin polarization effect, which provides an alternative approach to realization of spin-polarized electrons into semiconductors and may be of practical importance for spin-based nanodevice applications.

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