A5002925638- Graphene research and applications
- Topological Materials and Phenomena
- Quantum and electron transport phenomena
- Magnetic properties of thin films
- Advanced Condensed Matter Physics
- Chemical and Physical Properties of Materials
- Surface and Thin Film Phenomena
- Ionosphere and magnetosphere dynamics
- Physics of Superconductivity and Magnetism
- Earthquake Detection and Analysis
- 2D Materials and Applications
- Carbon Nanotubes in Composites
- Aluminum Alloys Composites Properties
- Geomagnetism and Paleomagnetism Studies
- Magnetic and transport properties of perovskites and related materials
- Diamond and Carbon-based Materials Research
- Advancements in Battery Materials
- Geophysics and Gravity Measurements
- Advanced Memory and Neural Computing
- Ferroelectric and Negative Capacitance Devices
- Silicon Carbide Semiconductor Technologies
- Solar and Space Plasma Dynamics
- Heusler alloys: electronic and magnetic properties
- Quantum optics and atomic interactions
- Phase-change materials and chalcogenides
St Petersburg University
2015-2024
Institute of Solar-Terrestrial Physics
2021-2024
Helmholtz-Zentrum Berlin für Materialien und Energie
2013
This paper reports spin-dependent valence-band dispersions of graphene synthesized on Ni(111) and subsequently intercalated with monolayers Au, Cu Bi. We have previously shown that after intercalation Au the dispersion π band remains linear in region point surface Brillouin zone even though system exhibits a noticeable hybridization between states d Au. also demonstrated giant spin–orbit splitting Au-intercalated which can reach up to ∼100 meV. In this we probe detail π–Au hybridized bands....
The electronic and spin structure of a graphene monolayer synthesized on Pt(111) has been investigated experimentally by angle- spin-resolved photoemission with different polarizations incident synchrotron radiation using density functional theory calculations. It is shown that despite the observed total quasifreestanding character dispersion $\ensuremath{\pi}$ state remarkable local distortions breaks in dispersions take place due to hybridization between Pt $d$ states. Corresponding...
A rich class of spintronics-relevant phenomena require implementation robust magnetism and/or strong spin–orbit coupling (SOC) to graphene, but both properties are completely alien it. Here, we for the first time experimentally demonstrate that a quasi-freestanding character, exchange splitting and giant SOC perfectly achievable in graphene at once. Using angle- spin-resolved photoemission spectroscopy, show Dirac state Au-intercalated on Co(0001) experiences (up 0.2 eV) while being by no...
High-resolution spin- and angle-resolved photoemission spectroscopy measurements were performed on the three-dimensional topological insulator Bi${}_{2}$Te${}_{2.4}$Se${}_{0.6}$, which is characterized by enhanced thermoelectric properties. The Fermi level position found to be located in bulk energy gap independent of temperature it stable over a long time. Spin textures Dirac-cone state at energies above below Dirac point as well Rashba-type valence band surface are observed agreement with...
Spin electronic structure of the Graphene/Pt interface has been investigated. A large induced spin-orbit splitting (∼80 meV) graphene π states with formation non-degenerated Dirac-cone spin at K¯-point Brillouin zone crossed spin-polarized Pt 5d Fermi level was found. We show that this can be used as a current source in spintronic devices. By theoretical estimations and micromagnetic modeling based on experimentally observed splitting, we demonstarte intrinsic magnetic field such might...
We investigated the magnetic properties of antiferromagnetic (AFM) topological insulator MnBi2Te4 with a partial substitution Mn atoms by non-magnetic elements (AIV = Ge, Pb, Sn). Samples various element concentrations (10–80%) were studied using SQUID magnetometry. The results demonstrate that, for all substitutes type ordering remains AFM, while Néel temperature (TN) and spin-flop transition field (HSF) decrease an increasing AIV Sn concentration. rate varies among elements, being highest...
Possibility of in-plane and out-of-plane magnetization generated by synchrotron radiation (SR) in magnetically doped pristine topological insulators (TIs) is demonstrated studied angle-resolved photoemission spectroscopy. We show experimentally ab initio calculations how nonequal depopulation the Dirac cone (DC) states with opposite momenta V-doped TIs linearly polarized SR leads to hole-generated uncompensated spin accumulation followed SR-induced via spin-torque effect. Moreover,...
The non-volatile spin-orbit torque magnetic random access memory (SOT-MRAM) is a very attractive technology for near future computers because it has various advantages such as non-volatility, high density and scalability. In the present work we propose model of graphene recording device SOT-MRAM unit cell, consisting quasi-freestanding intercalated with Au an ultra-thin Pt layer sandwiched between tunnel junction. As result using claimed element, faster operation lower energy consumption...
We show that graphene can be magnetized by coupling to a ferromagnetic Co film through Au monolayer. The presence of dislocation loops under leads ferrimagnetic ordering moments in the two C sublattices. It is shown band gap ∼80 meV K[over ¯] point has magnetic nature and exists for ordering. Interplay between Rashba exchange couplings evidenced spin splitting asymmetry spin-ARPES measurements fully supported DFT calculation (9×9) unit cell. Owing sign-opposite Berry curvatures ¯]^{'}...
The paper sums up a theoretical and experimental investigation of the influence spin–orbit coupling in W(110) on spin structure electronic states deposited Au Cu monolayers. Angle-resolved photoemission spectroscopy reveals that case monolayers split bands are formed surface-projected gap W(110). Spin resolution shows these polarized that, therefore, splitting is Rashba type. evolve from hybridization W 5d, 6p-derived with s, p metal. Interaction shifts original 5d-derived edges toward...
A modification of the contact graphene with ferromagnetic electrodes in a model spin filter allowing restoration electronic structure is proposed. It suggested for this aim to intercalate into interface between and (Ni or Co) electrode Au monolayer block strong interaction Ni (Co) and, thus, prevent destruction which evolves direct (Co). also insert an additional buffer size limited by that main sheet providing current transport Au/Ni injecting current. This will properties from influencing...
Modification of the electronic and crystal structure zero-layer graphene grown on $6H$-SiC(0001) after Co intercalation is reported. Using a wide range techniques including angle-resolved photoelectron spectroscopy, x-ray Raman low-energy electron diffraction, we found that SiC transforms into monolayer as result cobalt intercalation. The Dirac cone $\ensuremath{\pi}$ band characteristic quasi-freestanding observed. In combination with high-resolution transmission microscopy atomic force...
By means of angle- and spin-resolved photoemission, we demonstrate a possibility the out-of-plane spin polarization topological surface states corresponding lifting Kramers degeneracy at Dirac point induced in magnetically-doped insulator Bi1.37V0.03Sb0.6Te2Se by circularly polarized synchrotron radiation (SR) room temperature. It has been shown that is created due to an “optically”-generated uncompensated accumulation with transferring torque diluted V 3d ions. We have found theoretically...
We have studied an energy gap opening at the Kramers point of quasi-2D Rashba semiconductor BiTeI with magnetic doping and influence circularly polarized synchrotron radiation (SR) on induced out-of-plane spin polarization gapped state. By means angle- spin-resolved photoemission spectroscopy we shown that below a Curie temperature, 15–20 K, spontaneous anomalously large appears up to 90 125 meV depending V concentration (0.5 2%, respectively). Nevertheless, measurements show only weak both...
The spin-orbit splitting of graphene $\ensuremath{\pi}$ states can be strongly enhanced by external influences such as corrugation or proximity to heavier atoms. Here we investigate experimentally and theoretically whether strong enhancement is possible for on SiC(0001). By spin- angle-resolved photoemission found two independently grown samples no resolvable with an upper limit our analysis 20 meV. Our ab initio calculations predict a low 0.05 meV small anisotropy but local tenfold where...
Effect of magnetization generated by synchrotron or laser radiation in magnetically-doped and pristine topological insulators (TIs) is presented analyzed using angle-resolved photoemission spectroscopy. It was found that non-equal photoexcitation the Dirac cone (DC) states with opposite momenta spin orientation indicated asymmetry intensity DC accompanied k||-shift relative to non-spin-polarized conduction band located at k|| = 0. We relate observed induced surface in-plane magnetic field...
Intercalation of noble metals can produce giant Rashba-type spin–orbit splittings in graphene. The splitting more than 100 meV has yet to be achieved graphene on metal or semiconductor substrates. Here, we report the p-type obtained by Pt intercalation zero-layer SiC substrate. spin ∼200 was observed at a wide range binding energies. Comparing results theoretical studies different models with experimental ones measured spin-ARPES, XPS and STM methods, concluded that inducing requires not...
The spin structure of quantum well states (QWSs) in three-monolayer-thick gold overlayers on W(110) and Mo(110) is studied experimentally by spin- angle-resolved photoelectron spectroscopy theoretically ab initio calculations. spin–orbit coupling effects manifest themselves differently the atomic-like d delocalized sp QWSs depending how strongly are influenced substrate. a character show strong polarization with an almost identical for Mo(110), suggesting weak interaction substrate, whereas...