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Related papers: Predicting a Gapless Spin-1 Neutral Collective Mod…

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The one-loop polarization function of graphene has been calculated at zero temperature for arbitrary wavevector, frequency, chemical potential (doping), and band gap. The result is expressed in terms of elementary functions and is used to…

Strongly Correlated Electrons · Physics 2008-12-12 P. K. Pyatkovskiy

In an earlier work we predicted the existence of a neutral triplet collective mode in undoped graphene and graphite [Phys. Rev. Lett. {\bf 89} (2002) 16402]. In this work we study a phenomenological Hamiltonian describing the interaction of…

Strongly Correlated Electrons · Physics 2009-09-10 M. Ebrahimkhas , S. A. Jafari

This work was firstly published in 1986 \cite{we}. No real two-dimensional object with the zero-gap quasi-relativistic spectrum was known in that time. Such an object is well known now: this is graphene. That is why we decided to present it…

Mesoscale and Nanoscale Physics · Physics 2009-06-23 S. A. Ktitorov , Yu. V. Petrov

Using the Landau Fermi liquid theory we have discovered a new regime for the propagation of spin waves in a quasi-equilibrium spin systems. We have determined the dispersion relation for the transverse spin waves and found that one of the…

Strongly Correlated Electrons · Physics 2009-11-11 Kevin S. Bedell , Hari P. Dahal

Electron systems that possess light-like dispersion relations or the conical Dirac spectrum, such as graphene and bismuth, have recently been shown to harbor unusual collective states in high magnetic fields. Such states are possible…

Mesoscale and Nanoscale Physics · Physics 2009-10-08 D. Hsieh , Y. Xia , D. Qian , L. Wray , J. H. Dil , F. Meier , L. Patthey , J. Osterwalder , A. V. Fedorov , H. Lin , A. Bansil , D. Grauer , Y. S. Hor , R. J. Cava , M. Z. Hasan

Spin-polarized two-dimensional materials with large and tunable spin-splitting energy promise the field of 2D spintronics. While graphene has been a canonical 2D material, its spin properties and tunability are limited. Here, we demonstrate…

Coulomb screening and excitation spectra of electrons in a graphene layer with spin-orbit interaction (SOI) is studied in the random phase approximation. The SOI opens a gap between the valence and conduction bands of the semi-metal Dirac…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 X. F. Wang , Tapash Chakraborty

Radio-frequency compressed ultrafast electron diffraction has been used to probe the coherent and incoherent coupling of impulsive electronic excitation at 1.55 eV (800 nm) to optical and acoustic phonon modes directly from the perspective…

Materials Science · Physics 2015-06-23 Robert P. Chatelain , Vance R. Morrison , Bart L. M. Klarenaar , Bradley J. Siwick

Spin-1/2 particles such as the electron are described by the Dirac equation, which allows for two spin eigenvalues (up or down) and two types of energy eigenvalues (positive or negative, corresponding to the electron and the positron). A…

Mesoscale and Nanoscale Physics · Physics 2015-03-13 Matthew Mecklenburg , B. C. Regan

We study the energy and the static spin structure factor of the ground state of the spin-1/2 quantum Heisenberg antiferromagnetic model on the kagome lattice. By the iterative application of a few Lanczos steps on accurate projected…

Strongly Correlated Electrons · Physics 2015-03-20 Yasir Iqbal , Federico Becca , Sandro Sorella , Didier Poilblanc

Electrons in graphene are described by relativistic Dirac-Weyl spinors with a two-component pseudospin1-12. The unique pseudospin structure of Dirac electrons leads to emerging phenomena such as the massless Dirac cone2, anomalous quantum…

The Landau level spectrum of graphene superlattices is studied using a tight-binding approach. We consider non-interacting particles moving on a hexagonal lattice with an additional one-dimensional superlattice made up of periodic square…

Mesoscale and Nanoscale Physics · Physics 2012-06-28 G. Pal , W. Apel , L. Schweitzer

We study the Bloch spectrum and spin physics of 2D massless Dirac electrons in single layer graphene subject to a one dimensional periodic Kronig-Penney potential and Rashba spin-orbit coupling. The Klein paradox exposes novel features in…

Mesoscale and Nanoscale Physics · Physics 2021-08-18 Y. Avishai , Y. B. Band

In this work, we investigate the massive Kane-Mele model for graphene in the presence of disclination and an external magnetic field, where graphene behaviors as a topological insulator. In the low-energy limit, the effective field equation…

Mesoscale and Nanoscale Physics · Physics 2024-07-08 G. Q. Garcia , J. R. S. Oliveira , P. J. Porfírio , C. Furtado

Electron correlation effects caused by the topological zero mode of a hydrogenated graphene vacancy, $V_{111}$, with three adsorbed hydrogen atoms is discussed theoretically. A Kondo model is derived from the multi-reference representation…

Mesoscale and Nanoscale Physics · Physics 2014-12-31 Naoki Morishita , Gagus Ketut Sunnardianto , Koichi Kusakabe , Isao Maruyama , Kazuyuki Takai , Toshiaki Enoki

The application of a perpendicular electric field can drive silicene into a gapless state, characterized by two nearly fully spin-polarized Dirac cones owing to both relatively large spin-orbital interactions and inversion symmetry…

Mesoscale and Nanoscale Physics · Physics 2013-09-30 Yan-Yang Zhang , Wei-Feng Tsai , Kai Chang , X. -T. An , G. -P. Zhang , X. -C. Xie , Shu-Shen Li

We set up a field theory model to describe the longitudinal low energy modes in high density matter present in white dwarf stars. At the relevant scales, ions -- the nuclei of oxygen, carbon and helium -- are treated as heavy point-like…

High Energy Physics - Phenomenology · Physics 2016-02-10 Gregory Gabadadze , Rachel A Rosen

Off-diagonal disorder with random hopping between the sublattices of a bipartite lattice is described by a Hamiltonian which has chiral (sub-lattice) symmetry. The energy spectrum is symmetric around E=0 and for odd total number of lattice…

Disordered Systems and Neural Networks · Physics 2013-04-23 I. Kleftogiannis , S. N. Evangelou

The phenomenon of spin-dependent quantum scattering in two-dimensional (2D) pseudospin-1/2 Dirac materials leading to a relativistic quantum chimera was recently uncovered. We investigate spin-dependent Dirac electron optics in 2D…

Mesoscale and Nanoscale Physics · Physics 2024-08-23 Li-Li Ye , Chen-Di Han , Ying-Cheng Lai

We study the electron spectral function of various zero-temperature spin-charge separated phases in two dimensions. In these phases, the electron is not a fundamental excitation of the system, but rather ``decays'' into a spin-1/2…

Strongly Correlated Electrons · Physics 2009-11-07 C. Lannert , Matthew P. A. Fisher , T. Senthil