Rashba spin orbit

Borophene, owing to the high mobility and long spin coherent length of its carriers, presents significant opportunities in ultrafast spintronics. In this research, we investigate the spin-dependent conductance of a Datta-Das field-effect transistor (FET) based on an armchair β12 -borophene nanoribbon (BNR) using the tight-binding (TB) Hamiltonian in combination with the non-equilibrium Green's function (NEGF) method. The spin FET electrodes are magnetized by ferromagnetic (FM) insulators arranged in both parallel and anti-parallel configurations...

Polar metals have recently garnered increasing interest because of their promising functionalities. Here we report the experimental realization of an intrinsic coexisting ferromagnetism, polar distortion and metallicity in quasi-two-dimensional Ca3 Co3 O8 . This material crystallizes with alternating stacking of oxygen tetrahedral CoO4 monolayers and octahedral CoO6 bilayers. The ferromagnetic metallic state is confined within the quasi-two-dimensional CoO6 layers, and the broken inversion symmetry arises simultaneously from the Co displacements...

Nonlinear transport is a unique functionality of noncentrosymmetric systems, which reflects profound physics, such as spin-orbit interaction, superconductivity and band geometry. However, it remains highly challenging to enhance the nonreciprocal transport for promising rectification devices. Here, we observe a light-induced giant enhancement of nonreciprocal transport at the superconducting and epitaxial CaZrO3 /KTaO3 (111) interfaces. The nonreciprocal transport coefficient undergoes a giant increase with three orders of magnitude up to 105  A-1 T-1 ...

Motivated by the report of the giant Rashba effect in ternary layered compounds BiTeX, we consider two Janus structured compounds Ti2 N2 XI (X = Br, Cl) of the same ternary family exhibiting a 1 : 1 : 1 stoichiometric ratio. Broken inversion symmetry in the Janus structure, together with its unique electronic structure exhibiting anti-crossing states formed between Ti-d states and strong spin-orbit coupled I-p states, generates large Rashba cofficients of 2-3 eV Å for these compounds, classifying them as strong Rashba compounds...

The Rashba parameter α_{R} is usually assumed to scale linearly with the amplitude of polar displacements by construction of the spin-orbit interaction. On the basis of first-principles simulations, ferroelectric phases of SrTiO_{3} reached under epitaxial compressive strain are characterized by (i) large Rashba effects at the bottom of the conduction band near the paraelectric-ferroelectric boundary and (ii) an unexpected suppression of the phenomena when the amplitude of polar displacements increases...

Spin-orbit interactions arise whenever the bulk inversion symmetry and/or structural inversion symmetry of a crystal is broken providing a bridge between a qubit's spin and orbital degree of freedom. While strong interactions can facilitate fast qubit operations by all-electrical control, they also provide a mechanism to couple charge noise thereby limiting qubit lifetimes. Previously believed to be negligible in bulk silicon, recent silicon nano-electronic devices have shown larger than bulk spin-orbit coupling strengths from Dresselhaus and Rashba couplings...

Inorganic-organic lead halide perovskites, particularly methylammonium lead halide (MAPbI3 ) perovskite, have been regarded as promising materials for optoelectronics and spintronics. However, the practical applications of these perovskites are limited by lead toxicity and instability under air and pressure. This study investigates the substitution of Pb with Sn and Ge in cubic MAPbI3 perovskite. The properties of the resulting hybrid perovskites are compared using state-of-the-art first-principles-based methodologies, viz...

The two-dimensional electron gas (2DEG) at oxide interfaces exhibits extraordinary properties such as 2D superconductivity and ferromagnetism coupled to strongly-correlated electrons in narrow d-bands. In particular, 2DEGs in KTaO3 (KTO) with 5d t2g orbitals exhibit larger atomic spin-orbit coupling and crystal-facet-dependent superconductivity absent for 3d 2DEGs in SrTiO3 (STO). Herein, by tracing the interfacial chemistry, weak anti-localization magneto-transport behavior and electronic structures of (001), (110), and (111) KTO 2DEGs, we discovered unambiguously cation exchange across KTO interfaces...

Two-dimensional (2D) valley materials are promising materials for writing and storing information. The search for 2D materials with large valley splitting is essential for the development of spintronics and valley electronics. In this study, we theoretically design 2D W2 NSCl MXenes with large valley splitting based on first-principle calculations. Due to the strong spin-orbit coupling (SOC) and the broken inversion symmetry, the W2 NSCl monolayer exhibits valley splitting values of 491 meV and 83 meV at K / K ' of the valence and conduction bands, respectively...

Orbital current has emerged over the past years as one of the key novel concepts in magnetotransport. Here, we demonstrate that laser pulses can be used to generate large and robust nonrelativistic orbital currents in systems where the inversion symmetry is broken by the orbital Rashba effect. By referring to model and first principles tools, we demonstrate that orbital Rashba effect, accompanied by crystal field splitting, can mediate robust orbital photocurrents without a need for spin-orbit interaction even in metallic systems...

Low dimensional organic inorganic metal halide materials have shown broadband emission and large Stokes shift, making them widely used in various fields and a promising candidate material. Here, the zero-dimensional lead-free bromide single crystals (C6 H14 N)3 Bi2 Br9 ·H2 O ( 1 ) and (C6 H14 N)3 Sb3 Br12 ( 2 ) were synthesized. They crystallized in the monoclinic crystal system with the space group of P 21 and P 21 / n , respectively. Through ultraviolet-visible-near-infrared (UV-vis-NIR) absorption analysis, the band gaps of (C6 H14 N)3 Bi2 Br9 ·H2 O and (C6 H14 N)3 Sb3 Br12 are found to be 2...

We study the impact of the Rashba spin-orbit coupling (RSOC) on the stability of charge-density wave (CDW) in systems with large electron-phonon coupling (EPC). Here, the EPC is considered in the framework of the Holstein model at the half-filled square lattice. We obtain the phase diagram of the Rashba-Holstein model using the Hartree-Fock mean-field theory, and identify the boundaries of the CDW and Rashba metal phases. We notice that the RSOC disfavors the CDW phase, driving the system to a correlated Rashba metal...

Implementing topological superconductivity (TSC) and Majorana states (MSs) is one of the most significant and challenging tasks in both fundamental physics and topological quantum computations. In this work, taking the obstructed atomic insulator (OAI) Nb_{3}Br_{8}, s-wave superconductor (SC) NbSe_{2}, and ferromagnetic insulator (FMI) CrI_{3} as an example, we propose a new setup to realize the 2D chiral TSC and MSs in the SC/OAI/FMI heterostructure, which could avoid the subband problem effectively and has the advantage of huge Rashba spin-orbit coupling...

In general, hydrostatic pressure can suppress ferroelectric polarization and further reduce Rashba spin-splitting, considering the spin-orbit coupling effect. Here, we present the design of ferroelectric double perovskite Cs2 SnSiI6 , which exhibits the anomalous enhancement of Rashba spin-splitting parameters by pressure-induced ferroelectric topological order. The Rashba effect is nonlinear with the decrease in polarization under pressure and reaches a maximum at the pressure-induced Weyl semimetal (WSM) state between the transition from a normal insulator (NI) to a topological insulator (TI)...

The control and active manipulation of spin-orbit coupling (SOC) in photonic systems are fundamental in the development of modern spin optics and topological photonic devices. Here, we demonstrate the control of an artificial Rashba-Dresselhaus (RD) SOC mediated by photochemical reactions in a microcavity filled with an organic single crystal of photochromic phase-change character. Splitting of the circular polarization components of the optical modes induced by photonic RD SOC is observed experimentally in momentum space...

We study the influence of mechanical deformations on the Zeeman and Rashba effects in transition metal dichalcogenide (TMD) nanotubes and their Janus variants from first principles. In particular, we perform symmetry-adapted density functional theory simulations with spin-orbit coupling to determine the variation in the electronic band structure splittings with axial and torsional deformations. We find significant effects in molybdenum and tungsten nanotubes, for which the Zeeman splitting decreases with increase in strain, going to zero for large enough tensile/shear strains, while the Rashba splitting coefficient increases linearly with shear strain, while being zero for all tensile strains, a consequence of the inversion symmetry remaining unbroken...

Metals, renowned for their high reflectivity, find extensive use in various technological applications, from mirrors to optical coatings in radars, telescopes, and mobile communications. However, their potential in antireflective coatings has remained largely untapped. In this study, we demonstrate that by applying an ultrathin metallic film onto an oxide layer, we can achieve a flawless optical surface with zero reflectivity. This phenomenon has been successfully observed across various metals, including Sn, Ag, Au, Pt, Bi, and Nb, showcasing its broad applicability...

Controlling spin current in topological insulators (TIs) is a crucial requirement for applications in quantum computing and spintronics. Using the non-equilibrium Keldysh Green's function formalism, we demonstrate that such control can be established around rectangular cavities of two-dimensional TIs by breaking their time reversal symmetry via exchange magnetic fields and magnetic defects. In the presence of magnetic defects with xy symmetry or Ising symmetry, the density of states is localized, and the spin current forms a current loop around the rectangular cavity in TIs interfacing with two ferromagnetic stripes...

Chiral lead halide perovskites (LHPs) have been widely investigated in chiroptical spintronics due to their significant Rashba spin-orbit coupling (SOC) and chiral-induced spin selectivity (CISS). Ferromagnet/LHP spinterface stems from the orbital hybridization at the interface of the ferromagnet and the nonmagnetic semiconductor, where interfacial density of state is spin-dependent. By far, the impact of the ferromagnet/chiral LHP spinterface on magneto-photoluminescence (Magneto-PL) of chiral LHPs remains unknown...

Materials showing second-order nonlinear transport under time reversal symmetry can be used for Radio Frequency (RF) rectification, but practical application demands room temperature operation and sensitivity to microwatts level RF signals in the ambient. In this study, we demonstrate that BiTeBr exhibits a giant nonlinear response which persists up to 350 K. Through scaling and symmetry analysis, we show that skew scattering is the dominant mechanism. Additionally, the sign of the nonlinear response can be electrically switched by tuning the Fermi energy...