Read by QxMD icon Read

Rashba spin orbit

Satoru Hayami, Yukitoshi Motome
We theoretically study noncoplanar spin textures in polar magnetic conductors. Starting from the Kondo lattice model with the Rashba spin-orbit coupling, we derive an effective spin model with generalized Ruderman-Kittel-Kasuya-Yosida interactions including the anisotropic and antisymmetric exchange interactions. By performing simulated annealing for the effective model, we find that a vortex crystal of Néel type is stabilized even in the absence of a magnetic field. Moreover, we demonstrate that a Bloch-type vortex crystal, which is usually associated with the Dresselhaus spin-orbit coupling, can also be realized in our Rashba-based model...
September 28, 2018: Physical Review Letters
Liying Zhang, Wei Qin, Leiqiang Li, Shunfang Li, Ping Cui, Yu Jia, Zhenyu Zhang
As a highly appealing new member of the two-dimensional (2D) materials family, stanene was first epitaxially grown on a three-dimensional topological insulator of Bi2Te3; yet, to date, a standing challenge is to drastically improve the overall quality of such stanene overlayers for a wide range of potential applications in next-generation quantum devices. Here we use state-of-the-art first-principles approaches to explore the atomistic growth mechanisms of stanene on different Bi2Te3(111)-based substrates, with intriguing discoveries...
October 18, 2018: Nanoscale
Yuan Ping, Jin Zhong Zhang
Spin is an intrinsic quantum mechanical property of fundamental particles including the electron. The spin property is intimately related to electronic and optical properties of molecules and materials. The combination of spin (magnetic), electronic, and optical properties of materials, such as organometal halide perovskites (OMHP), has attracted increasing attention, which has led to a new field termed spin-optotronics based on all three key properties. This growing field has implications in emerging technological applications across disciplines, including photonics, electronics, spintronics, quantum computation, and information storage...
October 8, 2018: Journal of Physical Chemistry Letters
Zhizhou Yu, Jian Chen, Lei Zhang, Yanxia Xing, Jian Wang
Manipulating the magnetization of ferromagnets by the current-induced spin-orbit torque has great potential application in the design of low energy consumption spintronic devices. Normally, an external magnetic field is needed for the reversal of current assisted magnetization by the spin-orbit torque. Recently, the switching of magnetization driven by the spin-orbit torque in the absence of an external magnetic field was reported in a Ta/Co20 Fe60 B20 /TaOx system with lateral structural asymmetry. To understand the physics behind this experiment, we performed first principles calculations on the potential profile at the interface between the ferromagnetic film and the wedge-shaped deposited metal oxide in the Ta/Co/TaO system...
October 21, 2018: Nanoscale
C-T Chou, N T Jacobson, J E Moussa, A D Baczewski, Y Chuang, C-Y Liu, J-Y Li, T M Lu
Gate-controllable spin-orbit coupling is often one requisite for spintronic devices. For practical spin field-effect transistors, another essential requirement is ballistic spin transport, where the spin precession length is shorter than the mean free path such that the gate-controlled spin precession is not randomized by disorder. In this letter, we report the observation of a gate-induced crossover from weak localization to weak anti-localization in the magneto-resistance of a high-mobility two-dimensional hole gas in a strained germanium quantum well...
September 26, 2018: Nanoscale
Jian Sun, Russell S Deacon, Rui Wang, Jun Yao, Charles M Lieber, Koji Ishibashi
Helical states, a prerequisite for the engineering of Majorana zero modes in solid-state systems, have recently been reported in the conduction band of III-V nanowires (NWs) subject to strong Rashba spin-orbit interaction. We report the observation of re-entrant conductance features consistent with the presence of helical hole states in multiple conduction modes of a Ge/Si core/shell NW. The Ge/Si system has several potential advantages over electron systems such as longer spin coherence time due to weaker coupling to nuclear spins and the possibility of isotope-purified materials for nuclear spin-free devices...
September 19, 2018: Nano Letters
I A Ado, A Qaiumzadeh, R A Duine, A Brataas, M Titov
Dzyaloshinskii-Moriya interaction (DMI) is investigated in a 2D ferromagnet (FM) with spin-orbit interaction of Rashba type at finite temperatures. The FM is described in the continuum limit by an effective s-d model with arbitrary dependence of spin-orbit coupling (SOC) and kinetic energy of itinerant electrons on the absolute value of momentum. In the limit of weak SOC, we derive a general expression for the DMI constant D from a microscopic analysis of the electronic grand potential. We compare D with the exchange stiffness A and show that, to the leading order in small SOC strength α_{R}, the conventional relation D=(4mα_{R}/ℏ)A, in general, does not hold beyond the Bychkov-Rashba model...
August 24, 2018: Physical Review Letters
Folkert K de Vries, Jie Shen, Rafal J Skolasinski, Michal P Nowak, Daniel Varjas, Lin Wang, Michael Wimmer, Joost Ridderbos, Floris A Zwanenburg, Ang Li, Sebastian Koelling, Marcel A Verheijen, Erik P A M Bakkers, Leo P Kouwenhoven
Low dimensional semiconducting structures with strong spin-orbit interaction (SOI) and induced superconductivity attracted great interest in the search for topological superconductors. Both the strong SOI and hard superconducting gap are directly related to the topological protection of the predicted Majorana bound states. Here we explore the one-dimensional hole gas in germanium silicon (Ge-Si) core-shell nanowires (NWs) as a new material candidate for creating a topological superconductor. Fitting multiple Andreev reflection measurements shows that the NW has two transport channels only, underlining its one-dimensionality...
October 10, 2018: Nano Letters
L Dell'Anna, P Majari, M R Setare
We calculate the transmission coefficient for a particle crossing a potential barrier in monolayer graphene with Rashba spin-orbit coupling and in bilayer graphene. We show that in both cases one can go from Klein tunneling regime, characterized by perfect normal transmission, to anti-Klein tunneling regime, with perfect normal reflection, by tuning the Rashba spin-orbit coupling for a monolayer or the interplane coupling for a bilayer graphene. We show that the intermediate regime is characterized by a non-monotonic behavior with oscillations and resonances in the normal transmission amplitude as a function of the coupling and of the potential parameters...
October 17, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Cong Xiao, Bangguo Xiong, Fei Xue
In model studies of the spin/anomalous Hall effect, effective Hamiltonians often serve as the starting point. However, a complete effective quantum theory contains not only the effective Hamiltonian but also the relation linking the physical observables to the canonical ones. In this work we construct the semiclassical Boltzmann transport framework in the weak disorder-potential regime directly in the level of the effective quantum theory, and confirm this construction by formulating a generalized Kohn-Luttinger density matrix transport theory also in this level...
October 17, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
E Marcellina, A Srinivasan, D S Miserev, A F Croxall, D A Ritchie, I Farrer, O P Sushkov, Dimitrie Culcer, A R Hamilton
Semiconductor holes with strong spin-orbit coupling allow all-electrical spin control, with broad applications ranging from spintronics to quantum computation. Using a two-dimensional hole system in a gallium arsenide quantum well, we demonstrate a new mechanism of electrically controlling the Zeeman splitting, which is achieved through altering the hole wave vector k. We find a threefold enhancement of the in-plane g-factor g_{∥}(k). We introduce a new method for quantifying the Zeeman splitting from magnetoresistance measurements, since the conventional tilted field approach fails for two-dimensional systems with strong spin-orbit coupling...
August 17, 2018: Physical Review Letters
Lin Hu, Huaqing Huang, Zhengfei Wang, W Jiang, Xiaojuan Ni, Yinong Zhou, V Zielasek, M G Lagally, Bing Huang, Feng Liu
We theoretically demonstrate that screw dislocation (SD), a 1D topological defect widely present in semiconductors, exhibits ubiquitously a new form of spin-orbit coupling (SOC) effect. Differing from the widely known conventional 2D Rashba-Dresselhaus (RD) SOC effect that typically exists at surfaces or interfaces, the deep-level nature of SD-SOC states in semiconductors readily makes it an ideal SOC. Remarkably, the spin texture of 1D SD-SOC, pertaining to the inherent symmetry of SD, exhibits a significantly higher degree of spin coherency than the 2D RD-SOC...
August 10, 2018: Physical Review Letters
Cong Son Ho, Seng Ghee Tan, Shun-Qing Shen, Mansoor B A Jalil
Spin-orbit torque (SOT) refers to the excitation of magnetization dynamics via spin-orbit coupling (SOC) under the application of a charged current. In this work, we introduce a simple and intuitive description of the SOT in terms of spin force. In Rashba SOC system, the damping-like SOT can be expressed as [Formula: see text], in analogy to the classical torque-force relation, where R c is the effective radius characterizing the Rashba splitting in the momentum space. As a consequence, the magnetic energy is transferred to the conduction electrons, which dissipates through Joule heating at a rate of [Formula: see text], with j e being the applied current...
October 3, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Ryohei Wakatsuki, Naoto Nagaosa
We study theoretically the nonreciprocal charge transport in two-dimensional noncentrosymmetric superconductors with the Rashba spin-orbit interaction. The resistivity R depends on the current I linearly under the external magnetic field B, i.e., R=R_{0}(1+γBI), which is called the magnetochiral anisotropy. It is found that the coefficient γ is gigantically enhanced by the superconducting fluctuation with the components of both spin singlet and triplet pairings, compared with that in the normal state. This finding offers a method to quantitatively estimate the ratio of the pairing interactions between the singlet and triplet channels including its sign...
July 13, 2018: Physical Review Letters
Fernando Ajejas, Adrian Gudín, Ruben Guerrero, Alberto Anadón Barcelona, Jose Manuel Diez, Leticia de Melo Costa, Pablo Olleros, Miguel Angel Niño, Stefania Pizzini, Jan Vogel, Manuel Valvidares, Pierluigi Gargiani, Mariona Cabero, Maria Varela, Julio Camarero, Rodolfo Miranda, Paolo Perna
A major challenge for future spintronics is to develop suitable spin transport channels with long spin lifetime and propagation length. Graphene can meet these requirements, even at room temperature. On the other side, taking advantage of the fast motion of chiral textures, that is, Néel-type domain walls and magnetic skyrmions, can satisfy the demands for high-density data storage, low power consumption, and high processing speed. We have engineered epitaxial structures where an epitaxial ferromagnetic Co layer is sandwiched between an epitaxial Pt(111) buffer grown in turn onto MgO(111) substrates and a graphene layer...
August 1, 2018: Nano Letters
Jian Gou, Long-Juan Kong, Wen-Bin Li, Shao-Xiang Sheng, Hui Li, Sheng Meng, Peng Cheng, Ke-Hui Wu, Lan Chen
Two-dimensional surface structures often host a surface state in the bulk gap, which plays a crucial role in the surface electron transport. The diversity of in-gap surface states extends the category of two-dimensional systems and gives us more choices in material applications. In this article, we investigated the surface states of β-√3 × √3-Bi/Si(111) surface by scanning tunneling microscopy. Two nearly free electron states in the bulk gap of silicon were found in the unoccupied states. Combined with first-principles calculations, these two states were verified to be the Bi-contributed surface states and electron-accumulation-induced quantum well states...
August 1, 2018: Physical Chemistry Chemical Physics: PCCP
R I Mohamed, Ahmed Farouk, A H Homid, O H El-Kalaawy, Abdel-Haleem Abdel-Aty, M Abdel-Aty, S Ghose
We analyze the dynamics of squeezing in a ballistic quantum wire with Rashba spin-orbit interaction in the presence of both strong and weak magnetic fields and for different initial states of the system. Compared to the more standard measure of squeezing based on variances, we show that entropy squeezing is a more sensitive measure. Our results show that there is a strong relationship between the spin-orbit interaction and the strength of entropy squeezing. Furthermore, there is a relationship between the initial state and the number of squeezed components...
July 11, 2018: Scientific Reports
Szczepan Głodzik, Aksel Kobiałka, Anna Gorczyca-Goraj, Andrzej Ptok, Grzegorz Górski, Maciej M Maśka, Tadeusz Domański
We investigate single and multiple defects embedded in a superconducting host, studying the interplay between the proximity-induced pairing and interactions. We explore the influence of the spin-orbit coupling on energies, polarization and spatial patterns of the bound (Yu-Shiba-Rusinov) states of magnetic impurities in a two-dimensional square lattice. We also address the peculiar bound states in the proximitized Rashba chain, resembling the Majorana quasiparticles, focusing on their magnetic polarization that has been recently reported by S...
2018: Beilstein Journal of Nanotechnology
Jorge Cayao, Annica M Black-Schaffer, Elsa Prada, Ramón Aguado
Hybrid superconductor-semiconductor nanowires with Rashba spin-orbit coupling are arguably becoming the leading platform for the search of Majorana bound states (MBSs) in engineered topological superconductors. We perform a systematic numerical study of the low-energy Andreev spectrum and supercurrents in short and long superconductor-normal-superconductor junctions made of nanowires with strong Rashba spin-orbit coupling, where an external Zeeman field is applied perpendicular to the spin-orbit axis. In particular, we investigate the detailed evolution of the Andreev bound states from the trivial into the topological phase and their relation with the emergence of MBSs...
2018: Beilstein Journal of Nanotechnology
Alexander López, Francisco Mireles, John Schliemann, Benjamin Santos
We study the pseudospin and spin dynamical effects in single-layer silicene due to a perpendicular electric field periodically driven and its interplay with the intrinsic and extrinsic (Rashba) spin-orbit interaction. We find that the spin nonconserving processes of the real spin of the quasiparticles in silicene, induced by the rather weak spin-orbit mechanisms, manifest themselves as shifts of the resonances of its quasienergy spectrum in the low coupling regime to the driving field. We show that there is an interesting cooperative effect among the, in principle, competing Rashba and intrinsic spin-orbit contributions...
August 22, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"