scholarly journals Interface Engineering to Create a Strong Spin Filter Contact to Silicon

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
C. Caspers ◽  
A. Gloskovskii ◽  
M. Gorgoi ◽  
C. Besson ◽  
M. Luysberg ◽  
...  
Keyword(s):  
Interface Engineering ◽  
Spin Filter ◽  
Strong Spin

CONTROLLABLE SPIN-FILTERING AND MAGNETOCONDUCTANCE IN A NOVEL HYBRID FM/2DEG/FM STRUCTURE

2003 ◽  
Vol 17 (27n28) ◽  
pp. 1437-1444
Author(s):  
Y. JIANG ◽  
M. B. A. JALIL
Keyword(s):  
Ballistic Transport ◽  
Spin Valve ◽  
Fringe Field ◽  
Dimensional Electron ◽  
Spin Filter ◽  
Field Sweep ◽  
Magnetization Direction ◽  
Dimensional Electron Gas ◽  
Strong Spin ◽  
Spin Filtering

Spin-dependent ballistic transport is studied for a two-dimensional electron gas (2DEG) heterostructure, sandwiched between two ferromagnetic metal (FM) layers. The device exhibits a strong spin-filtering behavior when the magnetization directions of the FM layers are anti-parallel to one another. Additionally, a pronounced magnetoconductance (MC) effect is predicted when the relative magnetization direction of the FM layers is changed, e.g. by applying an external magnetic field sweep. Both the spin-filter and spin-valve (SV) functions can be tuned externally by adjusting the applied voltage and the fringe field strength from the FM layers. Compared to conventional all-metal SVs, the proposed 2DEG-based SV potentially has the advantages of a higher MC ratio (of as high as 90%), external tenability, and less susceptibility to interfacial imperfections.

Interface Engineering To Boost Photoresponse Performance of Self-Powered, Broad-Bandwidth PEDOT:PSS/Si Heterojunction Photodetector

2016 ◽  
Vol 8 (29) ◽  
pp. 19158-19167 ◽  
Author(s):  
Zhimin Liang ◽  
Pingyang Zeng ◽  
Pengyi Liu ◽  
Chuanxi Zhao ◽  
Weiguang Xie ◽  
...  
Keyword(s):  
Interface Engineering ◽  
Broad Bandwidth ◽  
Self Powered

scholarly journals Observation of chiral surface excitons in a topological insulator Bi2Se3

2019 ◽  
Vol 116 (10) ◽  
pp. 4006-4011 ◽  
Author(s):  
H.-H. Kung ◽  
A. P. Goyal ◽  
D. L. Maslov ◽  
X. Wang ◽  
A. Lee ◽  
...  
Keyword(s):  
Polarized Light ◽  
Orbit Coupling ◽  
Experimental Investigations ◽  
Composite Particles ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Excitation Energies ◽  
Circularly Polarized Light ◽  
Pl Emission ◽  
Strong Spin

The protected electron states at the boundaries or on the surfaces of topological insulators (TIs) have been the subject of intense theoretical and experimental investigations. Such states are enforced by very strong spin–orbit interaction in solids composed of heavy elements. Here, we study the composite particles—chiral excitons—formed by the Coulomb attraction between electrons and holes residing on the surface of an archetypical 3D TI,Bi2Se3. Photoluminescence (PL) emission arising due to recombination of excitons in conventional semiconductors is usually unpolarized because of scattering by phonons and other degrees of freedom during exciton thermalization. On the contrary, we observe almost perfectly polarization-preserving PL emission from chiral excitons. We demonstrate that the chiral excitons can be optically oriented with circularly polarized light in a broad range of excitation energies, even when the latter deviate from the (apparent) optical band gap by hundreds of millielectronvolts, and that the orientation remains preserved even at room temperature. Based on the dependences of the PL spectra on the energy and polarization of incident photons, we propose that chiral excitons are made from massive holes and massless (Dirac) electrons, both with chiral spin textures enforced by strong spin–orbit coupling. A theoretical model based on this proposal describes quantitatively the experimental observations. The optical orientation of composite particles, the chiral excitons, emerges as a general result of strong spin–orbit coupling in a 2D electron system. Our findings can potentially expand applications of TIs in photonics and optoelectronics.

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