Spin transport study in a Rashba spin-orbit coupling system

Abstract

One of the most important topics in spintronics is spin transport. In this work, spin transport properties of two-dimensional electron gas in AlxGa1-xN/GaN heterostructure were studied by helicity-dependent photocurrent measurements at room temperature. Spin-related photocurrent was detected under normal incidence of a circularly polarized laser with a Gaussian distribution. On one hand, spin polarized electrons excited by the laser generate a diffusive spin polarization current, which leads to a vortex charge current as a result of anomalous circular photogalvanic effect. On the other hand, photo-induced spin polarized electrons driven by a longitudinal electric field give rise to a transverse current via anomalous Hall Effect. Both of these effects originated from the Rashba spin-orbit coupling. By analyzing spin-related photocurrent varied with laser position, the contributions of the two effects were differentiated and the ratio of the spin diffusion coefficient to photo-induced anomalous spin Hall mobility Ds/μs = 0.08 V was extracted at room temperature.

SnO­2 Tailored by CuO for Improved CH4 Sensing at Low Temperature

“…[4][5][6] Tin oxide (SnO 2 ), a typical gas-sensing material, has been intensively studied for toxic gas detection with various shapes and morphologies. [1,7] It is also excellent candidate for transparent conducting substrates with doping with In and F, as anode materials for Li-ion batteries and catalyst applications. [1,8,9] On the other hand, CuO, a monoclinic crystal system, is a p-type semiconductor and is also a potential candidate for solar cell fabrications, catalytic applications, and gas sensors.…”

Facile Biopolymer Assisted Synthesis of Hollow SnO2 Nanostructures and Their Application in Dye Removal

“…[4] Nanostructured SnO 2 are of great interest because of the quantum confinement effect in nanometer dimension where the size, shape and surface states are the predominant factors to influence their optical, electronic and catalytic properties. [1,5,6] Also it is possible to tune its band gap so as to modify the optoelectronic properties and consequently it finds wide applications in areas such as gas sensing, [7][8][9][10][11] transparent conductive electrodes, [1,12] rechargeable Li ion batteries, [13,14] solar cells, [15,16] and photocatalysis. [17,18] Such promising applications and the favorable properties prompted material scientists to synthesize SnO 2 nanostructures of controlled sizes and shapes such as nanoparticles, [8,19] nanowires, [10,20] and hollow nanostructures.…”

“…[1,5,6] Also it is possible to tune its band gap so as to modify the optoelectronic properties and consequently it finds wide applications in areas such as gas sensing, [7][8][9][10][11] transparent conductive electrodes, [1,12] rechargeable Li ion batteries, [13,14] solar cells, [15,16] and photocatalysis. [17,18] Such promising applications and the favorable properties prompted material scientists to synthesize SnO 2 nanostructures of controlled sizes and shapes such as nanoparticles, [8,19] nanowires, [10,20] and hollow nanostructures. [7, 16-18, 21, 22] Furthermore, hollow SnO 2 nanostructures possess higher surface area and hence attracted considerable attention because of their promising applications, such as highly reversible lithium storage [17,23] and dye-sensitized solar cells.…”

Spin transport in undoped InGaAs/AlGaAs multiple quantum well studied via spin photocurrent excited by circularly polarized light

“…The anomalous circular photogalvanic effect (ACPGE) [ 3 – 5 ] and anomalous Hall effect (AHE) [ 6 – 10 ], which are derived from the same spin-orbit coupling (SOC) mechanisms (intrinsic or extrinsic) based on the reciprocal spin Hall effect (RSHE), open avenues to the study of the relationship between the diffusion and the drift of photoinduced spin-polarized electrons. According to [ 11 ], the ratio of the diffusion coefficient to the mobility of the photoinduced spin-polarized electrons has been measured to be 0.08 V in AlGaN/GaN heterostructure with the excitation wavelength of 1064 nm at room temperature. In this work, we focused on the spectrum and temperature dependence of the transport properties corresponding to interband transitions in an undoped InGaAs/AlGaAs multiple quantum well (MQW) in which a strong Rashba SOC had been demonstrated in previous studies [ 10 , 12 , 13 ].…”