scholarly journals Surface atomic-layer superconductors with Rashba/Zeeman-type spin-orbit coupling

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Takashi Uchihashi
Keyword(s):  
Electronic Properties ◽  
Recent Progress ◽  
Experimental Studies ◽  
Atomic Layer ◽  
Surface Structures ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Future Prospects ◽  
Semiconductor Substrates

AbstractIn this article, we review the recent progress in surface atomic-layer superconductors on semiconductor substrates with Rashba/Zeeman-type spin-orbit coupling (SOC). After introduction of some of the basics of Rashba/Zeeman-type SOC and its effects on superconductivity, representative surface structures with relevant features are described in terms of their crystalline and electronic properties. This is followed by recent experimental studies that have revealed anomalous superconducting phenomena, which can be attributed to the effects of Rashba/Zeeman-type SOC. Future prospects, likely to be driven by instrumentational developments, are given as a concluding remark.

scholarly journals 5f Delocalization of Bulk FCC Americium and the (111) Surface: A FP-LAPW Electronic Structure Study

2005 ◽  
Vol 893 ◽  
Author(s):  
Da Gao ◽  
Asok K Ray
Keyword(s):  
Electronic Properties ◽  
Local Density ◽  
Structure Study ◽  
Orbit Coupling ◽  
Full Potential ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Generalized Gradient ◽  
Quantum Size ◽  
Ferromagnetic Ground State

AbstractThe electronic properties of bulk fcc americium and the (111) surface have been investigated with the full-potential linearized augmented plane wave (FP-LAPW) method as implemented in the WIEN2K suite of programs The study is carried out for the anti-ferromagnetic ground state of Am at different levels of theory: (1) scalar-relativity vs. full-relativity; (2) local-density approximation (LDA) vs. generalized-gradient approximation (GGA). Our results indicate that spin orbit coupling plays an important role in determining the electronic properties of both bulk fcc americium and the (111) surface. In general, LDA is found to give a higher total energy compared to GGA results. The spin orbit coupling shows a similar effect on the surface calculations regardless of the model, GGA versus LDA. The 5f localized-delocalized transition of americium is employed to explain our results. In addition, the quantum size effects in the surface energies and the work functions of fcc (111) americium ultra thin films (UTF) are also examined.

scholarly journals Modulation of electronic properties from stacking orders and spin-orbit coupling for 3R-type MoS2

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiaofeng Fan ◽  
W. T. Zheng ◽  
Jer-Lai Kuo ◽  
David J. Singh ◽  
C.Q. Sun ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit

scholarly journals New type of Weyl semimetal with quadratic double Weyl fermions

2016 ◽  
Vol 113 (5) ◽  
pp. 1180-1185 ◽  
Author(s):  
Shin-Ming Huang ◽  
Su-Yang Xu ◽  
Ilya Belopolski ◽  
Chi-Cheng Lee ◽  
Guoqing Chang ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Experimental Realization ◽  
Weyl Semimetal ◽  
Chiral Magnetic Effect ◽  
Wide Range ◽  
Weyl Semimetals ◽  
Weyl Fermions

Weyl semimetals have attracted worldwide attention due to their wide range of exotic properties predicted in theories. The experimental realization had remained elusive for a long time despite much effort. Very recently, the first Weyl semimetal has been discovered in an inversion-breaking, stoichiometric solid TaAs. So far, the TaAs class remains the only Weyl semimetal available in real materials. To facilitate the transition of Weyl semimetals from the realm of purely theoretical interest to the realm of experimental studies and device applications, it is of crucial importance to identify other robust candidates that are experimentally feasible to be realized. In this paper, we propose such a Weyl semimetal candidate in an inversion-breaking, stoichiometric compound strontium silicide, SrSi2, with many new and novel properties that are distinct from TaAs. We show that SrSi2 is a Weyl semimetal even without spin–orbit coupling and that, after the inclusion of spin–orbit coupling, two Weyl fermions stick together forming an exotic double Weyl fermion with quadratic dispersions and a higher chiral charge of ±2. Moreover, we find that the Weyl nodes with opposite charges are located at different energies due to the absence of mirror symmetry in SrSi2, paving the way for the realization of the chiral magnetic effect. Our systematic results not only identify a much-needed robust Weyl semimetal candidate but also open the door to new topological Weyl physics that is not possible in TaAs.

Electronic structure and spin-orbit coupling in ternary transition metal chalcogenides Cu2TlX 2 (X=Se, Te)

2021 ◽  
Author(s):  
Na Qin ◽  
Xian Du ◽  
Yangyang Lv ◽  
Lu Kang ◽  
Zhongxu Yin ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Ab Initio ◽  
Band Gap ◽  
Electronic Properties ◽  
Orbit Coupling ◽  
Metal Chalcogenides ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Transition Metal Chalcogenides

Abstract Ternary transition metal chalcogenides provide a rich platform to search and study intriguing electronic properties. Using Angle-Resolved Photoemission Spectroscopy and ab initio calculation, we investigate the electronic structure of Cu2TlX 2 (X = Se, Te), ternary transition metal chalcogenides with quasi-two-dimensional crystal structure. The band dispersions near the Fermi level are mainly contributed by the Te/Se p orbitals. According to our ab-initio calculation, the electronic structure changes from a semiconductor with indirect band gap in Cu2TlSe2 to a semimetal in Cu2TlTe2, suggesting a band-gap tunability with the composition of Se and Te. By comparing ARPES experimental data with the calculated results, we identify strong modulation of the band structure by spin-orbit coupling in the compounds. Our results provide a ternary platform to study and engineer the electronic properties of transition metal chalcogenides related to large spin-orbit coupling.

scholarly journals Spin-orbit coupling effect on electronic, linear and nonlinear optical properties of Bi2S3 and the Ternary Bismuth Sulfide Bi2S2.75Se0.25: Ab-initio calculations

2021 ◽  
Author(s):  
Houda Ben Abdallah ◽  
Walid Ouerghui
Keyword(s):  
Optical Properties ◽  
Nonlinear Optical ◽  
Experimental Studies ◽  
Orbit Coupling ◽  
Optical Absorption Coefficient ◽  
Optical Parameters ◽  
High Electron ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Bismuth Sulfide

Abstract Although the relevant properties of the bismuthinite \({Bi}_{2}{S}_{3}\), it was recently approved that the substitution of Se atoms in the \({Bi}_{2}{S}_{3}\) lattice can significantly enhance its electro-optical properties. In the present work, a detailed study on the structural, electronic and optical properties of \({Bi}_{2}{S}_{2.75}{Se}_{0.25}\) has been carried out based on first principle calculations. The simultaneous effect of Se-doping and spin-orbit coupling (SOC) on bismuth sulfide \({Bi}_{2}{S}_{3}\) was investigated. Our calculations show that \({Bi}_{2}{S}_{2.75}{Se}_{0.25}\) exhibits a narrow direct band gap of 1.062 eV after inclusion of the (SOC). The calculation of the carrier effective masses indicates that \({Bi}_{2}{S}_{2.75}{Se}_{0.25}\) may possess a high electron mobility material which is in accordance with experimental studies. The linear absorption optical spectra for both \({Bi}_{2}{S}_{3}\) and \({Bi}_{2}{S}_{2.75}{Se}_{0.25}\)show that doping bismuthinite with (Se) increases the optical absorption coefficient in the visible range and takes a value up to \(10 {10}^{5}{cm}^{-1}\). In addition, the dielectric function, optical conductivity and the energy loss function of \({Bi}_{2}{S}_{3}\) and \({Bi}_{2}{S}_{2.75}{Se}_{0.25}\)were also derived. The addition of the (Se) content induces a red shift in agreement with experimental studies. A noticeable effect of the (SOC) on the linear optical parameters was observed. The stability of the excitons was also studied by the estimation of the binding energy value. The dispersion energy parameters of \({Bi}_{2}{S}_{3}\) and \({Bi}_{2}{S}_{2.75}{Se}_{0.25}\)were estimated using a single oscillator model. Some nonlinearities have been computed with and without inclusion of (SOC) showing that \({Bi}_{2}{S}_{2.75}{Se}_{0.25}\)with large nonlinear optical parameters is promising candidate in photonic switching applications.

Stable structures and superconductivity of an At–H system at high pressure

2018 ◽  
Vol 20 (38) ◽  
pp. 24783-24789 ◽  
Author(s):  
Ziji Shao ◽  
Yanping Huang ◽  
Defang Duan ◽  
Yanbin Ma ◽  
Hongyu Yu ◽  
...  
Keyword(s):  
Phase Diagram ◽  
High Pressure ◽  
Electronic Properties ◽  
First Principles ◽  
Orbit Coupling ◽  
First Principles Calculation ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Stable Structures

The phase diagram, electronic properties and superconductivity of an At–H system at high pressure are investigated through first principles calculation considering the effect of spin–orbit coupling (SOC).

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