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Specular Andreev Reflection In The Interface Of A Two-Dimensional Semiconductor With Rashba Spin-Orbit Coupling And A D-Wave Superconductor, Bo Lv, C Zhang, Zhongshui Ma
Specular Andreev Reflection In The Interface Of A Two-Dimensional Semiconductor With Rashba Spin-Orbit Coupling And A D-Wave Superconductor, Bo Lv, C Zhang, Zhongshui Ma
Faculty of Engineering - Papers (Archive)
We reveal that the recently discovered specular Andreev reflection (SAR) [C. W. J. Beenakker, Phys. Rev. Lett. 97, 067007 (2006)] can occur in semiconductors where the spin-orbit coupling is finite. We demonstrate this finding in the hybrid of a two-dimensional electron gas with Rashba spin-orbit coupling and a superconductor. In the limit of low density or a strong spin-orbit coupling, specular Andreev reflection is finite. We also show that unit electron-hole conversion is possible in a specular Andreev reflection due to the different topological structures of the equal-energy surface between electrons and holes. The SAR in the semiconductor is determined …
Structural Dependent Ultrafast Electron-Phonon Coupling In Multiferroic Bifeo 3 Films, Zuanming Jin, Yue Xu, Zhengbing Zhang, Gaofang Li, Xian Lin, Guohong Ma, Zhenxiang Cheng, Xiaolin Wang
Structural Dependent Ultrafast Electron-Phonon Coupling In Multiferroic Bifeo 3 Films, Zuanming Jin, Yue Xu, Zhengbing Zhang, Gaofang Li, Xian Lin, Guohong Ma, Zhenxiang Cheng, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
The electronic energy relaxation of polycrystalline BiFeO3 films is studied using ultrafast pump-probe spectroscopy. After photo-excitation with femtosecond laser pulses, the relaxation of hot electrons is identified to decay with two different characteristic times. The fast process is attributed to scattering of electrons with lattice-vibration modes, and the slow one is corresponding to the spin-lattice thermalization. The electron-phonon coupling is characterized by the second moment of the Eliashberg function, khx2i. Due to the structural strain and symmetry breaking, the electron-phonon interaction strength of tetragonal BiFeO3 films is larger than that of rhombohedral counterparts
Coupling Effects Of Feed Solution Ph And Ionic Strength On The Rejection Of Boron By Nf/Ro Membranes, Kha Tu, Long Nghiem, Allan Chivas
Coupling Effects Of Feed Solution Ph And Ionic Strength On The Rejection Of Boron By Nf/Ro Membranes, Kha Tu, Long Nghiem, Allan Chivas
Faculty of Engineering - Papers (Archive)
The coupling effects of solution pH and ionic strength on boron rejection by nanofiltration (NF) and reverse osmosis (RO) membranes were investigated. Two NF membranes (namely NF270 and NF90) and three RO membranes (namely BW30, SW30 and UTC80) were used to provide a full spectrum of NF/RO membranes. The rejection of boron by all five membranes was pH-dependent. The dependency of boron rejection on the feed solution pH became much more substantial as the nominal salt (sodium or calcium) rejection value of the membrane decreased. At pH 11, boron rejections by the NF90 and the NF270 membranes were only 10% …
Two-Color Terahertz Response In Bilayer Graphene Nanoribbons With Spin-Orbit Coupling, Junfeng Liu, Bo Wang, Zhongshui Ma, Chao Zhang
Two-Color Terahertz Response In Bilayer Graphene Nanoribbons With Spin-Orbit Coupling, Junfeng Liu, Bo Wang, Zhongshui Ma, Chao Zhang
Faculty of Engineering - Papers (Archive)
We demonstrate that spin-orbit coupling can give rise to a strong terahertz response in metallic armchair bilayer graphene nanoribbons. The combination of the interlayer coupling and the spin-orbit coupling leads to double resonant optical response in the low frequency regime. The frequency separation of the two excitations is tunable with a gate voltage.
Coupling Interaction Of Electromagnetic Wave In A Groove Doublet Configuration, Lan Ding, Jinsong Liu, Kejia Wang, Dong Wang
Coupling Interaction Of Electromagnetic Wave In A Groove Doublet Configuration, Lan Ding, Jinsong Liu, Kejia Wang, Dong Wang
Faculty of Engineering - Papers (Archive)
Based on the waveguide mode (WGM) method, coupling interaction of electromagnetic wave in a groove doublet configuration is studied. The formulation obtained by WGM method for a single groove [Prog. Electromagn. Res. 18, 1–17 (1998)] is extended to two grooves. By exploring the total scattered field of the configuration, coupling interaction ratios are defined to describe the interaction between grooves quantitatively. Since each groove in this groove doublet configuration is regarded as the basic unit, the effects of coupling interaction on the scattered fields of each groove can be investigated respectively. Numerical results show that an oscillatory behavior of …
Enhancement Of Polarization In A Spin-Orbit Coupling Quantum Wire With A Constriction, Chao Zhang, Zhi-Cheng Zhong, Dingping Li, Zhongshui Ma, Lei Chen, Junfeng Liu
Enhancement Of Polarization In A Spin-Orbit Coupling Quantum Wire With A Constriction, Chao Zhang, Zhi-Cheng Zhong, Dingping Li, Zhongshui Ma, Lei Chen, Junfeng Liu
Faculty of Engineering - Papers (Archive)
We investigate the enhancement of spin polarization in a quantum wire in the presence of a constriction and a spin-orbit coupling segment. It is shown that the spin-filtering effect is significantly heightened in comparison with the configuration without the constriction. It is understood in the studies that the constriction structure plays a critical role in enhancing the spin filtering by means of confining the incident electrons to occupy one channel only while the outgoing electrons occupy two channels. The enhancement of spin filtering has also been analyzed within the perturbation theory. Because the spin polarization arises mainly from the scattering …
Gate-Tunable Ruderman-Kittel-Kasuya-Yosida Interaction Mediated By Low-Dimensional Electrons With Rashba Spin-Orbit Coupling, Pin Lyu, Ning-Ning Liu, Chao Zhang
Gate-Tunable Ruderman-Kittel-Kasuya-Yosida Interaction Mediated By Low-Dimensional Electrons With Rashba Spin-Orbit Coupling, Pin Lyu, Ning-Ning Liu, Chao Zhang
Faculty of Engineering - Papers (Archive)
The gate-controllable Ruderman-Kittel-Kasuya-Yosida RKKY magnetic interaction between themagnetic impurities embedded in one- and two-dimensional electron gas in the presence of Rashbaspin-orbit coupling was analyzed theoretically. By using the eigenfunctions of the single-particleRashba Hamiltonian as the basis of second quantization, we derived the RKKY interaction by fullytaking into account the spin-orbit interaction. The dependence of the RKKY magnetic interaction onthe Rashba spin-orbit coupling strength was obtained numerically. Our results clearly indicate thatthe RKKY interaction can be significantly modified by an applied voltage via the Rashba spin-orbitcoupling.