Electrical transport property is closely related to the dimensionality of carriers distribution. Therefore the spin orbit interaction can indeed be viewed as analogous to a zeeman splitting in an effective magnetic field, except that in the present case, there is no time reversal symmetry. The calculation of transmission probability is based on an effective mass quantummechanical approach in the presence of an. We show that in both the cases one can go from klein tunneling regime, characterized by perfect normal transmission, to antiklein tunneling regime, with perfect normal reflection, by tuning the rashba spin. Rashba field k b r n current induces steady rashba field m y b b y r 2. Rashbatype spinorbit coupling in bilayer boseeinstein. Analogue of rashba pseudospinorbit coupling in photonic. Rashba spinorbit coupling enhanced carrier lifetime in. Majorana end states in multiband microstructures with. With our plane wave ansatz for the y direction, the spin orbit hamiltonian hso can be written as fig. Magnetosubbands of semiconductor quantum wires with. However, its insignificant intrinsic spinorbit coupling leads to weak spin charge conversion and hinders its application in spin transport electronics. Inducing rashba spin orbit coupling in hexagonal monolayers graphene and its siblings, transition metal dichalcogenides, etc. A promising way to achieve this goal is to make use of the tunable.
For instance, a spin splitting of about 100 mev has been reported in graphene in contact with au111, although other substrates such as ni111 or bi111 have proven. Pdf theoretical model for rashba spinorbit interaction. Mar 03, 2020 we propose an experimental realization of the spin hall effect in graphene by illuminating a graphene sheet on top of a substrate with circularly polarized monochromatic light. In heterostructures with broken inversion symmetry, the electrons motion is coupled to their spin through interfacedriven spin orbit coupling. On the other hand, the extrinsic spin orbit coupling of the bychkov rashba type. An important ingredient of the ddt is the spin orbit coupling of the rashba 810 or dresselhaus 11,12 types. Spinorbit coupling strength in ev for the outermost electrons in the atoms considered in this work as obtained from the hydrogenic expression. A key concept in the emerging field of spintronics is the voltagegate control of spin precession via the effective magnetic field generated by the rashba spin orbit coupling soc.
We demonstrate that the synergistic effect of a gauge field, rashba spin orbit coupling soc, and zeeman splitting can generate chaotic cyclotron and hall trajectories of particles. The lack of inversion symmetry results in an effective electric field perpendicular to the basal plane of px, hence, leading to rashba type spin orbit coupling soc in the two dimensional px nanosheets. The spin orbit force, different from that in conventional semiconductors, can provide us a physical picture of. Rashba and other spin orbit interactions yuli lyandageller department of physics and birck nanotechnology center, purdue university work in progress in collaboration with m. F so j f so j s more spin up electrons are deflected to the right than to the left and viceversa for spin down for a given deflection, spin up and spin down electrons make a side. The coupling is found irrelevant to the value of the intrinsic spin orbit induced gap. Magnetosubbands of semiconductor quantum wires with rashba. The anticrossing between the second and third subband is marked by a circle. Photoprotected spin hall effect on graphene with substrate.
Vortex structures of rotating spinorbitcoupled bose. The magnetic anisotropy energy mae resulting from the rashba spin orbit and sd type exchange interactions is determined for two different models of afms. Electrostatically gating a material with strong soc results in an effective magnetic field which can in turn be used to govern the electron spin. Based on the transfermatrix method and the group velocity concept, we investigate theoretically the spin tunneling time through single and double barriers of diluted magnetic semiconductor structures in the presence of the rashba spin. Realistic rashba and dresselhaus spinorbit coupling for. Gatetunable rashba spinorbit coupling and spin polarization. The superconductivity with rashba and dressehlaus spinorbit coupling and zeeman effect is investigated. Jul 15, 2007 therefore, measurements of the spinorbit coupling initially focused on the rashba term in qws and concentrated on the study of beatings in shubnikovde haas oscillations 8,10,11,12, whose. In 1984, bychkov and rashba introduced a simple form of spinorbit coupling to explain the peculiarities of electron spin resonance in twodimensional semiconductors. Rashba effect vs dresselhaus effect spin orbit coupling. Effects of rashba spinorbit coupling, zeeman splitting and. Unlike the conventional form, the ishe can be induced without the need for spin current injection from an external source. The former one is due to the interaction of spin and motion of an electron 14, 17, 18, and the later one originates from the structural inversion asymmetry due to a potential gradient.
Both of these effects originated from the rashba spin orbit coupling. Over the past 30 years, rashba spin orbit coupling has inspired a vast number of predictions, discoveries. We study the possibility for the extraction of the rashba spin orbit coupling constant for a twodimensional electron gas with the conductance microscopy technique. Kondo effect in graphene with rashba spinorbit coupling. We start with a brief introduction on the origin of spinorbit splitting in asymmetrically grown 2deg, extended to metallic interfaces, and topological surfaces. Huge rashbatype spinorbit coupling in binary hexagonal. Inverse spin hall effect in ferromagnetic metal with. Effects of rashba spinorbit coupling, zeeman splitting. We report an intrinsic form of the inverse spin hall effect ishe in ferromagnetic fm metal with rashba spin orbit coupling rsoc, which is driven by a normal charge current. Herein, we demonstrate a tunable rashba spinorbit coupling soc and spin polarization of lamosto 0. Measurements of the inplane anisotropic magnetoresistance and the conductinglayer. From klein to antiklein tunneling in graphene tuning the.
We explore a way of producing the rashba spinorbit coupling soc for ultracold atoms by using a twocomponent spinor atomic boseeinstein condensate bec con. We calculate the transmission coefficient for a particle crossing a potential barrier in monolayer graphene with rashba spin orbit coupling and in bilayer graphene. Over the past 30 years, rashba spin orbit coupling has inspired a vast number of predictions, discoveries and innovative concepts far beyond semiconductors. The key idea of this device is that the orientation of spins of a twodimensional electron system 2des confined in a narrowgap semiconductor quantum well can be changed by the spin orbit interaction, providing both parallel and antiparallel. Spinorbit coupling can be enhanced by lifting the degenerate spin bands through strain gradient and rashba. In layered semiconductor heterostructure, there exists spin orbit coupling soc, which can induce electron spin polarization. An important component of this line of research is aimed at control and manipulation of electrons spin degrees of freedom in semiconductor quantum dot devices. Tightbinding theory of spin orbit coupling in graphynes. The global isb model, representing the effect of a surface, an interface, or a gating electric field, results in an easyplane magnetic anisotropy.
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 photoinduced anomalous spin hall mobility d s. Rashba spinorbit coupling in a twodimensional electron. Majorana end states in multiband microstructures with rashba spin orbit coupling. Magnetic anisotropy in an antiferromagnet afm with inversion symmetry breaking isb is investigated.
The substrate induces a controllable rashba type spin orbit coupling which breaks the spin degeneracy of the dirac cones but it is gapless. Large bychkovrashba spinorbit coupling in highmobility ganalgan heterostructures. In the landau gauge the unidimensional wave vector describing the free motion. The circularly polarized light induces a gap in the spectrum and turns graphene. The rashba effect, also called bychkov rashba effect, is a momentumdependent splitting of spin bands in bulk crystals and lowdimensional condensed matter systems such as heterostructures and surface states similar to the splitting of particles and antiparticles in the dirac hamiltonian. Electronic structure and anisotropic rashba spinorbit coupling in monolayer black phosphorus. In this work, we investigate the possible dramatic effects of rashba or dresselhaus spinorbit coupling soc on the fermionic hubbard model in a twodimensional square lattice. This rashba dresselhaus rd coupling scheme is described by a vector potential which can be made proportional to the spin 12 operator of a particle within a plane. It is found that the tpa is enhanced several times by rsoc effect which is tuned by the external electric field. Rashba spinorbit coupling in twodimensional systems. Rashba and weyl spinorbit coupling in an optical lattice.
Measurement of rashba and dresselhaus spinorbit magnetic. In this work, we succeed in tuning the carriers distribution and the rashba spin orbit coupling at laalo 3 srtio 3 interface by varying the oxygen pressure cp o2 adopted in crystalline laalo 3 growth. The rashba spin orbit coupling has a similar energy band splitting, but the asymmetry comes either from the bulk asymmetry of uniaxial crystals e. Electronic structure and anisotropic rashba spinorbit. The maximum spin splitting energy depends on the mn doping and decreases with the increasing. The rashba spinorbit coupling has a similar energy band splitting, but the asymmetry comes either from the bulk asymmetry of uniaxial crystals e.
In 1984, bychkov and rashba introduced a simple form of spin orbit coupling to explain the peculiarities of electron spin resonance in twodimensional semiconductors. Derivation of rashba spinorbit coupling in tightbinding. On the basis of firstprinciples calculations and a rashba spinorbit model, we demonstrate that the recombination rate is reduced due to the spinforbidden transition. Tightbinding theory of the spinorbit coupling in graphene. Enhanced spinorbit coupling in silicon escholarship. The physical origin of the chaotic behavior is that the soc produces a spin dependent socalled anomalous contribution to the particle velocity and the presence of zeeman field reduces the. Manipulating the electron spin with the aid of spin orbit coupling soc is an indispensable element of spintronics. Duine6 in 1984, bychkov and rashba introduced a simple form of spin orbit coupling to explain the peculiarities of electron spin resonance in twodimensional semiconductors. However, despite the significant progress in rashba physics, controlling the. The past decade has been particularly creative, with the realizations of. Contrary to the uncovered region of a shared singlelayer graphene flake, wal in ws 2covered graphene occurs over a wide range of carrier densities on both electron and hole sides. Duine6 in 1984, bychkov and rashba introduced a simple form of spinorbit coupling to explain the peculiarities of electron spin resonance in twodimensional semiconductors. The calculation of transmission probability is based on an effective mass quantummechanical approach.
We derive the effective spin orbit force in rashba coupled graphene from the heisenberg equation of motion. Rashba spinorbit interaction how is rashba spinorbit. In the strong coupling limit, it leads to the rotated antiferromagnetic heisenberg model which is a new class of quantum spin model. We theoretically propose that rashba type band splitting can be achieved in binary alloyed hexagonal px nanosheets x as, sb, and bi. Both of these effects originated from the rashba spinorbit coupling.
By analyzing spinrelated photocurrent varied with laser position, the contributions of the two effects were differentiated and the ratio of the spin diffusion coefficient to photoinduced anomalous spin hall mobility d s. Dykman workshop on quantum engineering with electrons on helium, may 21 2010, princeton nj. The derivation is highly dependent on which orbitals you have in the systems, p, d. The observation of rashba spin splitting in graphene on the ni 111 substrate, motivates the studies to manipulate electron spin via rashba spin orbit coupling in graphene. Therefore, measurements of the spin orbit coupling initially focused on the rashba term in qws and concentrated on the study of beatings in. We consider the energy spectrum of the twodimensional cavity polaritons under the influence of a strong magnetic and electric fields perpendicular to the surface of the gaastype quantum wells qws with ptype valence band embedded into the. Fermionic hubbard model with rashba or dresselhaus spinorbit. Magnetic anisotropy by rashba spinorbit coupling in. Spinorbit coupling and spin transport internet archive. Aug 31, 20 based on the transfermatrix method and the group velocity concept, we investigate theoretically the spin tunneling time through single and double barriers of diluted magnetic semiconductor structures in the presence of the rashba spin. The magnetic anisotropy energy mae resulting from the rashba spinorbit and sd type exchange interactions is determined for two different models of afms. Tuning rashba spinorbit coupling in gated multilayer inse. Herein, we demonstrate a tunable rashba spin orbit coupling soc and spin polarization of lamosto 0.
Spin transport study in a rashba spinorbit coupling system. New perspectives for rashba spinorbit coupling nature. Sandler 1department of physics and astronomy, and nanoscale and quantum phenomena institute, ohio university, athens, ohio 457012979, usa 2dahlem center for complex quantum systems and fachbereich physik, freie universitat berlin. Segev1 1physics department, technion israel institute of technology, haifa 32000, israel 2institute of applied physics, friedrichschiller. Engineering twodimensional superconductivity and rashba spin orbit coupling in laalo3srtio3 quantum wells by selective orbital occupancy. Extrinsic rashba spinorbit coupling effect on silicene spin. The global isb model, representing the effect of a surface, an interface, or a gating electric field, results in an easyplane. The rashba spin orbit coupling in carbon nanotubes and its effect on spin dependent transport properties are analyzed theoretically. In this work, we report the existence and electrostatic tunability of rashba soc in multilayer inse. Pdf electronic structure and anisotropic rashba spinorbit. Enhancement of rashba spinorbit coupling by electron. Rashba spinorbit coupling research papers academia. Electronic structure and anisotropic rashba spin orbit. Dresselhaus and rashba effects are often of similar strength in the band splitting of gaas nanostructures.
The rashba spin orbit coupling is typical for systems with uniaxial symmetry, e. Pdf electronic structure and anisotropic rashba spin. Tunable spinorbit coupling and symmetryprotected edge. We demonstrate clear weak antilocalization wal effect arising from induced rashba spin orbit coupling soc in ws 2covered singlelayer and bilayer graphene devices. Recent achievements in semiconductor spintronics are discussed. The influence of the rashba spinorbit coupling rsoc on the twodimensional 2d electrons and holes in a strong perpendicular magnetic field leads to different results for the landau quantization in different spin projections. Traditional external gate voltage usually needs a power supply, which can easily bring about background noise or lead to a short circuit in measurement, especially for nanoscale spintronic devices. Engineering twodimensional superconductivity and rashba. Rashba spin orbit coupling enhanced carrier lifetime in nh pbi. Orbit coupling enhanced carrier lifetime in ch3nh3pbi3 fan zheng, liang z. Special attention is paid to spin orbit interaction, coupling of electron spins to external. Rashba and other spinorbit interactions yuli lyandageller department of physics and birck nanotechnology center, purdue university work in progress in collaboration with m. However, its insignificant intrinsic spin orbit coupling leads to weak spin charge conversion and hinders its application in spin transport electronics.
There have been intense research efforts over the last years focused on understanding the rashba spin orbit coupling effect from the perspective of possible spintronics applications. The energy gaps of quasiparticles are carefully calculated. The soc of the rashba type is created if the atoms pick up a. Spin orbit coupling can be enhanced by lifting the degenerate spin bands through strain gradient and rashba effect, and further increased with proximity effect. These results are important for understanding the fundamental physics of organometal halide perovskites and for optimizing and designing the materials with better performance. Chaotic cyclotron and hall trajectories due to spinorbit. Generalized rashbadresselhaus spinorbit coupling for. The splitting is a combined effect of spin orbit interaction and asymmetry of the crystal potential. Pdf theoretical model for rashba spinorbit interaction in. Rashba spin orbit so coupling 3 has been proposed as a mechanism for spin control, not only because of the possibility of its external manipulation, but also because it is the physical origin of spin dependent phenomena such as anisotropic magnetoresistance. Download hires image download to mspowerpoint abstract a key concept in the emerging field of spintronics is the voltagegate control of spin precession via the effective magnetic field generated by the rashba spinorbit coupling soc.
Rappe, the makineni theoretical laboratories, department of chemistry, university of pennsylvania, philadelphia, pennsylvania 191046323, united states geophysical laboratory carnegie institution for science, washington, d. Electric field controlled spin interference in a system with. The presence of soc causes the of energy band into two splitting by a spin splitting energybranches. Piezotronic effect on rashba spinorbit coupling in a zno. Electric field controlled spin interference in a system. In a previous paper 17 we have presented an analysis of the diagonal magnetoresistivity in a 2des affected only by rashba spin orbit coupling, and this paper treats its effect on the hall magnetoresistivity at larger magnetic fields.
Extraction of the rashba spinorbit coupling constant from. Rashba spinorbit coupling in the kanemelehubbard model. The rashba hamiltonian describes the splitting of the conduction band as a result of spin orbit coupling in the presence of an external field and is commonly used to model the electronic structure of confined narrowgap semiconductors. Considering a realistic 3layered semiconductor heterostructure, insbin x ga 1x asgasb, we present a theoretical study of spin polarized transport by the rashba soc type. As the first step in this direction the landau quantization lq of the electrons and heavyholes hh was investigated taking into account the rashba spin orbit coupling rsoc with thirdorder chirality terms for hh and with nonparabolicity terms in their dispersion low including as well the zeeman splitting zs effects. Rashba spinorbit coupling effect on the quantum hall.
It is shown that the coexistence of two spinorbit coupling might suppress superconductivity. Spielman1 1joint quantum institute, national institute of standards and technology, and university of maryland, gaithersburg, maryland 20899, usa 2institute of theoretical physics and astronomy, vilnius university, a. Due to the mixing of spin states some care has to be exercised in the calculation of transport. Considering the spin of electron, some new effects such as intrinsic spinorbit coupling soc and rashba soc should be taken into account. The rashba effect enables the interconversion between spin and charge currents, offering a variety of novel spintronic phenomena and functionalities. Moreover, the zeeman effect favors spintriplet cooper pairs. Spinorbit force in graphene with rashba spinorbit coupling.
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