- 2D Crystals
Author(s): Li Wang and Libin Fu
We study the properties of an ultracold Fermi gas loaded in a square optical lattice and subjected to an external and classical non-Abelian gauge field. We calculate the energy spectrum of the system and show that the Dirac points in the energy spectrum will remain quite stable under on-site interac...
[Phys. Rev. A 87, 053612] Published Mon May 20, 2013
Author(s): Haijing Zhang, Jianming Lu, Wu Shi, Zhe Wang, Ting Zhang, Mingyuan Sun, Yuan Zheng, Qihong Chen, Ning Wang, Juhn-Jong Lin, and Ping Sheng
[Phys. Rev. Lett. 110, 209901] Published Mon May 13, 2013
Author(s): James V. Sloan, Alejandro A. Pacheco Sanjuan, Zhengfei Wang, Cedric Horvath, and Salvador Barraza-Lopez
We study the electronic properties of rippled freestanding graphene membranes under central load from a sharp tip. To that end, we develop a gauge field theory on a honeycomb lattice valid beyond the continuum theory. Based on the proper phase conjugation of the tight-binding pseudospin Hamiltonian,...
[Phys. Rev. B 87, 155436] Published Fri Apr 26, 2013
Author(s): Thomas Iadecola, David Campbell, Claudio Chamon, Chang-Yu Hou, Roman Jackiw, So-Young Pi, and Silvia Viola Kusminskiy
Controlling the properties of materials by driving them out of equilibrium is an exciting prospect that has only recently begun to be explored. In this Letter we give a striking theoretical example of such materials design: a tunable gap in monolayer graphene is generated by exciting a particular op...
[Phys. Rev. Lett. 110, 176603] Published Thu Apr 25, 2013
Author(s): Fernando de Juan, Juan L. Mañes, and María A. H. Vozmediano
We revise the tight-binding approach to strained or curved graphene in the presence of external probes such as photoemission or scanning tunneling microscopy experiments. We show that extra terms arise in the continuum limit of the tight-binding Hamiltonian which cannot be accounted for by changes i...
[Phys. Rev. B 87, 165131] Published Tue Apr 23, 2013
Author(s): Justin C. W. Song, Klaas J. Tielrooij, Frank H. L. Koppens, and Leonid S. Levitov
In materials with strong electron-electron interactions, photoexcitation can trigger a cascade in which multiple particle-hole excitations are generated. Here we analyze the cascade of impact-excitation processes in graphene in which many hot carriers are generated by a single absorbed photon. We sh...
[Phys. Rev. B 87, 155429] Published Tue Apr 23, 2013
Author(s): P. S. Alekseev, A. P. Dmitriev, I. V. Gornyi, and V. Yu. Kachorovskii
We study theoretically magnetoresistance (MR) of graphene with different types of disorder. For short-range disorder, the key parameter determining magnetotransport properties—a product of the cyclotron frequency and scattering time—depends in graphene not only on magnetic field H but also on the el...
[Phys. Rev. B 87, 165432] Published Tue Apr 23, 2013
Author(s): Alexander L. Kitt, Vitor M. Pereira, Anna K. Swan, and Bennett B. Goldberg
[Phys. Rev. B 87, 159909] Published Tue Apr 23, 2013
Author(s): J. Guillemette, S. S. Sabri, Binxin Wu, K. Bennaceur, P. E. Gaskell, M. Savard, P. L. Lévesque, F. Mahvash, A. Guermoune, M. Siaj, R. Martel, T. Szkopek, and G. Gervais
The quantum Hall effect is observed in a two-dimensional electron gas formed in millimeter-scale hydrogenated graphene, with a mobility less than 10 cm2/V·s and corresponding Ioffe-Regel disorder parameter (kFλ)-1≫1. In a zero magnetic field and low temperatures, the hydrogenated graphene is insula...
[Phys. Rev. Lett. 110, 176801] Published Mon Apr 22, 2013
Author(s): J. N. B. Rodrigues, P. A. D. Gonçalves, Jaime E. Santos, and A. H. Castro Neto
We construct a three-color Potts-like model for the graphene zigzag edge reconstructed with Stone-Wales carbon rings in order to study its thermal equilibrium properties. We consider two cases which have different ground states: the edge with nonpassivated dangling carbon bonds and the edge fully pa...
[Phys. Rev. B 87, 134204] Published Mon Apr 22, 2013
Author(s): Oleg L. Berman, Roman Ya. Kezerashvili, and Klaus Ziegler
A study of the formation of excitons as a problem of two Dirac particles in a gapped graphene layer and in two gapped graphene layers separated by a dielectric is presented. In the low-energy limit the separation of the center-of-mass and relative motions is obtained. Analytical solutions for the wa...
[Phys. Rev. A 87, 042513] Published Mon Apr 22, 2013
Author(s): Takashi Kajiwara, Yuzuru Nakamori, Anton Visikovskiy, Takushi Iimori, Fumio Komori, Kan Nakatsuji, Kazuhiko Mase, and Satoru Tanaka
[Phys. Rev. B 87, 159907] Published Fri Apr 19, 2013
Author(s): Pouyan Ghaemi, Sarang Gopalakrishnan, and Shinsei Ryu
Spatially inhomogeneous strains in graphene can simulate the effects of valley-dependent magnetic fields. As demonstrated in recent experiments [ N. Levy et al. Science 329 544 (2010) and K. K. Gomes et al. Nature (London) 483 306 (2012)], the realizable magnetic fields are large enough to give r...
[Phys. Rev. B 87, 155422] Published Wed Apr 17, 2013
Author(s): Oleksiy Kashuba and Vladimir I. Fal'ko
We study the fine structure of the phonon G peak in the inelastic light scattering spectra of strained graphene in the presence of a quantizing magnetic field. We show that under the conditions of magnetophonon resonance (MPR), the spectral line shape in Raman spectra of the Γ-point longitudinal opt...
[Phys. Rev. B 87, 161404] Published Tue Apr 16, 2013
Author(s): M. Pelc, L. Chico, A. Ayuela, and W. Jaskólski
We study graphene nanoribbons and carbon nanotubes containing ordered defect lines built of octagonal rings. We show that octagonal defect lines are a robust source of state localization at the Fermi energy, in some cases leading to spontaneous magnetization. We also prove that the localization at c...
[Phys. Rev. B 87, 165427] Published Mon Apr 15, 2013
Author(s): Frank Freitag, Markus Weiss, Romain Maurand, Jelena Trbovic, and Christian Schönenberger
We show nonlinear transport experiments on clean, suspended bilayer graphene that reveal a gap in the density of states. Looking at the evolution of the gap in magnetic fields of different orientation, we find that the ground state is a spin-ordered phase. Of the three possible gapped ground states ...
[Phys. Rev. B 87, 161402] Published Fri Apr 12, 2013
Author(s): Tim Gould, John F. Dobson, and S. Lebègue
In a Letter by Lebègue et al. Phys. Rev. Lett. 105 196401 (2010) describing benchmark ab initio adiabatic connection, fluctuation dissipation calculations under the random-phase approximation (ACFD-RPA) of graphite, it was demonstrated that the dispersion energy of uniaxially stretched graphite ob...
[Phys. Rev. B 87, 165422] Published Fri Apr 12, 2013
Author(s): Dmitry V. Fedorov, Martin Gradhand, Sergey Ostanin, Igor V. Maznichenko, Arthur Ernst, Jaroslav Fabian, and Ingrid Mertig
The effect of electron-impurity scattering on momentum and spin relaxation times in graphene is studied by means of relativistic ab initio calculations. Assuming carbon and silicon adatoms as natural impurities in graphene, we are able to simulate fast spin relaxation observed experimentally. We inv...
[Phys. Rev. Lett. 110, 156602] Published Fri Apr 12, 2013
Author(s): M. B. Lundeberg, R. Yang, J. Renard, and J. A. Folk
A principal motivation to develop graphene for future devices has been its promise for quantum spintronics. Hyperfine and spin-orbit interactions are expected to be negligible in single-layer graphene. Spin transport experiments, on the other hand, show that graphene’s spin relaxation is orders of m...
[Phys. Rev. Lett. 110, 156601] Published Thu Apr 11, 2013
Author(s): Sandeep Kumar Singh, M. Neek-Amal, and F. M. Peeters
Density-functional tight-binding and classical molecular dynamics simulations are used to investigate the structural deformations and melting of planar carbon nanoclusters CN with N=2–55. The minimum-energy configurations for different clusters are used as starting configurations for the study of th...
[Phys. Rev. B 87, 134103] Published Thu Apr 11, 2013
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