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Fletta eftir efnisorði "Þéttefnisfræði"

Fletta eftir efnisorði "Þéttefnisfræði"

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  • Kibis, Oleg; Dini, Kevin Tanguy Elian; Iorsh, Ivan; Shelykh, Ivan (American Physical Society (APS), 2017-03-01)
    We demonstrate theoretically that the interaction of electrons in gapped Dirac materials (gapped graphene and transition-metal dichalchogenide monolayers) with a strong off-resonant electromagnetic field (dressing field) substantially renormalizes the ...
  • Marques, Y.; Obispo, A. E.; Ricco, L. S.; de Souza, M.; Shelykh, Ivan; Seridonio, A. C (American Physical Society (APS), 2017-07-11)
    The ground state of the diatomic molecules in nature is inevitably bonding, and its first excited state is antibonding. We demonstrate theoretically that, for a pair of distant adatoms placed buried in three-dimensional-Dirac semimetals, this natural ...
  • Shahnazaryan, Vanik (University of Iceland, School of Engineering and Natural Sciences, Faculty of Physical Sciences, 2017-10)
    The physics of light-matter interactions is a rapidly developing interdisciplinary research area, combining methods and phenomena both from condensed matter physics and quantum optics. One of the most common realizations of strong coupling regime implies ...
  • Bessarab, Pavel (American Physical Society (APS), 2017-04-24)
    Rohart et al. [Phys. Rev. B 93, 214412 (2016)] recently reported calculations indicating two mechanisms for the annihilation of a skyrmion in a Co monolayer on Pt(111). The path calculations were based on a method presented in the Supplemental Material ...
  • Müller, Gideon Philipp; Bessarab, Pavel; Vlasov, Sergei M.; Lux, Fabian; Kiselev, Nikolai S.; Blügel, Stefan; Uzdin, Valery M.; Jónsson, Hannes (American Physical Society (APS), 2018-11-06)
    Various transitions that a magnetic Skyrmion can undergo are found in calculations using a method for climbing up the energy surface and converging onto first order saddle points. In addition to collapse and escape through a boundary, the method ...
  • Uzdin, Valery M.; Potkina, Maria N.; Lobanov, Igor S.; Bessarab, Pavel; Jónsson, Hannes (Elsevier BV, 2017-09)
    The stability of magnetic skyrmions against thermal fluctuations and external perturbations is investigated within the framework of harmonic transition state theory for magnetic degrees of freedom. The influence of confined geometry and atomic scale ...
  • Uzdin, V.M.; Potkina, M.N.; Lobanov, I.S.; Bessarab, Pavel; Jónsson, Hannes (Elsevier BV, 2017-11)
    The stability of skyrmions in various environments is estimated by analyzing the multidimensional surface describing the energy of the system as a function of the directions of the magnetic moments in the system. The energy is given by a Heisenberg-like ...
  • Whittaker, C. E.; Cancellieri, E.; Walker, P. M.; Gulevich, D. R.; Schomerus, H.; Vaitiekus, D.; Royall, B.; Whittaker, D. M.; Clarke, E.; Iorsh, Ivan; Shelykh, Ivan; Skolnick, M. S.; Krizhanovskii, D. N. (American Physical Society (APS), 2018-03-02)
    We study exciton polaritons in a two-dimensional Lieb lattice of micropillars. The energy spectrum of the system features two flat bands formed from S and P x , y photonic orbitals, into which we trigger bosonic condensation under high power ...
  • Shahnazaryan, Vanik; Iorsh, Ivan; Shelykh, Ivan; Kyriienko, O. (American Physical Society (APS), 2017-09-06)
    We study theoretically the Coulomb interaction between excitons in transition metal dichalcogenide (TMD) monolayers. We calculate direct and exchange interaction for both ground and excited states of excitons. The screening of the Coulomb interaction, ...
  • Haldar, Soumyajyoti; von Malottki, Stephan; Meyer, Sebastian; Bessarab, Pavel; Heinze, Stefan (American Physical Society (APS), 2018-08-27)
    We show that stable skyrmions with diameters of a few nanometers can emerge in atomic Pd/Fe bilayers on the Rh(111) surface. Based on density functional theory we calculate the exchange and the Dzyaloshinskii-Moriya interaction as well as the ...
  • Pervishko, Anastasiia A.; Yudin, Dmitry; Shelykh, Ivan (American Physical Society (APS), 2018-02-16)
    Lowering of the thickness of a thin-film three-dimensional topological insulator down to a few nanometers results in the gap opening in the spectrum of topologically protected two-dimensional surface states. This phenomenon, which is referred to as the ...
  • Bessarab, Pavel; Müller, Gideon Philipp; Lobanov, Igor S.; Rybakov, Filipp N.; Kiselev, Nikolai S.; Jónsson, Hannes; Uzdin, Valery M.; Blügel, Stefan; Bergqvist, Lars; Delin, Anna (Springer Nature, 2018-02-21)
    The skyrmion racetrack is a promising concept for future information technology. There, binary bits are carried by nanoscale spin swirls–skyrmions–driven along magnetic strips. Stability of the skyrmions is a critical issue for realising this technology. ...
  • Visan, Camelia; Anghel, D. V.; Nemnes, George Alexandru; Manolescu, Andrei (IOP Publishing, 2016-08)
    The hybrid graphene - hexagonal boron nitride (G-hBN) systems offer new routes in the design of nanoscale electronic devices. Using ab initio density functional theory calculations we investigate the dynamics of zig-zag nanoribbons a few interatomic ...
  • Dini, Kevin Tanguy Elian (University of Iceland, School of Engineering and Natural Sciences, Faculty of Physical Sciences, 2018)
    Light matter coupling is a eld that has rapidly grown in the past decades to become one of the most important interdisciplinary research subject. It combines the phenomena of condensed matter and quantum optics and brings a new panel of unique e ects. ...
  • Iorsh, Ivan; Dini, Kevin Tanguy Elian; Kibis, Oleg; Shelykh, Ivan (American Physical Society (APS), 2017-10-11)
    It is shown theoretically that the renormalization of the electron energy spectrum of bilayer graphene with a strong high-frequency electromagnetic field (dressing field) results in the Lifshitz transition—the abrupt change in the topology of the Fermi ...
  • Kozin, Valerii; Iorsh, Ivan; Kibis, Oleg; Shelykh, Ivan (American Physical Society (APS), 2018-01-11)
    We demonstrate theoretically that a strong high-frequency circularly polarized electromagnetic field can turn a two-dimensional periodic array of interconnected quantum rings into a topological insulator. The elaborated approach is applicable to calculate ...
  • Kozin, Valerii; Iorsh, Ivan; Kibis, Oleg; Shelykh, Ivan (American Physical Society (APS), 2018-04-26)
    We developed the theory of electronic properties of semiconductor quantum rings with the Rashba spin-orbit interaction irradiated by an off-resonant high-frequency electromagnetic field (dressing field). Within the Floquet theory of periodically driven ...
  • Marques, Y.; Yudin, D.; Shelykh, Ivan; Seridonio, A. C. (American Physical Society (APS), 2018-06-12)
    Recently, it was shown both theoretically and experimentally that certain three-dimensional (3D) materials have Dirac points in the Brillouin zone, thus being 3D analogs of graphene. Moreover, it was suggested that under specific conditions a pair of ...
  • Magnus, Fridrik; Warnatz, T.; Palsson, G. K.; Devishvili, A.; Ukleev, V.; Palisaitis, J.; Persson, P. O. Å.; Hjörvarsson, B. (American Physical Society (APS), 2018-05-24)
    Polarized neutron reflectometry is used to determine the sequence of magnetic switching in interlayer exchange coupled Fe/MgO(001) superlattices in an applied magnetic field. For 19.6 Å thick MgO layers we obtain a 90 ∘ periodic magnetic alignment ...
  • Erdmenger, Johanna; Fernández, Daniel; Flory, Mario; Megías, Eugenio; Straub, Ann-Kathrin; Witkowski, Piotr (Springer Nature, 2017-10)
    Within gauge/gravity duality, we consider the local quench-like time evolution obtained by joining two 1+1-dimensional heat baths at different temperatures at time t = 0. A steady state forms and expands in space. For the 2+1-dimensional gravity dual, ...