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The fine structure of the Dirac energy spectrum in graphene induced by electron-optical phonon coupling is investigated in the portion of the spectrum near the phonon emission threshold. The derived new dispersion equation in the immediate…

Mesoscale and Nanoscale Physics · Physics 2013-07-29 S. M. Badalyan , F. M. Peeters

Among its many outstanding properties, graphene supports terahertz surface plasma waves -- sub-wavelength charge density oscillations connected with electromagnetic fields that are tightly localized near the surface[1,2]. When these waves…

A major achievement of the past decade has been the realization of macroscopic quantum systems by exploiting interactions between optical cavities and mechanical resonators. In these systems, phonons are coherently annihilated or created in…

Mesoscale and Nanoscale Physics · Physics 2016-09-21 R. De Alba , F. Massel , I. R. Storch , T. S. Abhilash , A. Hui , P. L. McEuen , H. G. Craighead , J. M. Parpia

We investigate band-gap tuning of bilayer graphene between hexagonal boron nitride sheets, by external electric fields. Using density functional theory, we show that the gap is continuously tunable from 0 to 0.2 eV, and is robust to…

Materials Science · Physics 2015-05-20 Ashwin Ramasubramaniam , Doron Naveh , ELias Towe

The electron-phonon interaction in monolayer graphene is investigated by using density functional perturbation theory. The results indicate that the electron-phonon interaction strength is of comparable magnitude for all four in-plane…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 K. M. Borysenko , J. T. Mullen , E. A. Barry , S. Paul , Y. G. Semenov , J. M. Zavada , M. Buongiorno Nardelli , K. W. Kim

Graphene has shown great application potentials as the host material for next generation electronic devices. However, despite its intriguing properties, one of the biggest hurdles for graphene to be useful as an electronic material is its…

We investigate the role of the substrate for the strength of the electon phonon coupling in Li-decorated graphene. We find that the interaction with a $h$-BN substrate leads to a significant enhancement from $\lambda_0=0.62$ to…

Superconductivity · Physics 2013-12-17 T. P. Kaloni , A. V. Balatsky , U. Schwingenschlögl

Graphene is used as the thinnest possible spacer between gold nanoparticles and a gold substrate. This creates a robust, repeatable, and stable sub-nanometre gap for massive plasmonic field enhancements. White light spectroscopy of single…

Magneto Raman scattering study of the E$_{2g}$ optical phonons in multi-layer epitaxial graphene grown on a carbon face of SiC are presented. At 4.2K in magnetic field up to 33 T, we observe a series of well pronounced avoided crossings…

Materials Science · Physics 2015-05-13 C. Faugeras , M. Amado , P. Kossacki , M. Orlita , M. Sprinkle , C. Berger , W. A. de Heer , M. Potemski

A recipe on how to engineer a band gap in the energy spectrum for the carriers in graphene is conveyed. It is supported by a series of numerical simulations inspired by an analytical result based on the opening of a band gap in periodically…

Materials Science · Physics 2018-10-05 Stefan Kolev , Victor Atanasov , Hristiyan Aleksandrov , Teodor Milenov

We investigate the effect of electron- $\mathrm{A}_{1g}$ phonon coupling on the gapless electronic band dispersion of the pristine graphene. The electron-phonon interaction is introduced through a Kekul\'{e}-type distortion giving rise to…

Mesoscale and Nanoscale Physics · Physics 2013-10-29 B. S. Kandemir , A. Mogulkoc

Lacking a band gap largely limits the application of graphene in electronic devices. Previous study shows that grain boundaries (GBs) in polycrystalline graphene can dramatically alter the electrical properties of graphene. Here, we…

Materials Science · Physics 2013-01-11 Jiangtao Wu , Xinghua Shi , Yujie Wei

In this paper, we will introduce THz graphene antennas that strongly enhance the emission rate of quantum systems at specific frequencies. The tunability of these antennas can be used to selectively enhance individual spectral features. We…

Optics · Physics 2013-02-08 R. Filter , M. Farhat , M. Steglich , R. Alaee , C. Rockstuhl , F. Lederer

Plasmon and coupled plasmon-phonon modes in graphene are investigated the-oretically within the diagrammatic self-consistent field theory. It shows that two plasmon modes and four coupled plasmon-phonon modes can be excited via intra-and…

Mesoscale and Nanoscale Physics · Physics 2011-08-29 H. M. Dong , S. H. Zhang , W. Xu

Novel materials are in great demand for future applications. The discovery of graphene, a one atom thick carbon layer, holds the promise for unique device architectures and functionalities exploiting unprecedented physical phenomena. The…

Mesoscale and Nanoscale Physics · Physics 2011-01-25 M. F. Craciun , S. Russo , M. Yamamoto , S. Tarucha

We develop a theory for the electron-phonon interaction effects on the electronic properties of graphene. We analytically calculate the electron self-energy, spectral function and band velocity renormalization due to phonon-mediated…

Materials Science · Physics 2009-11-13 Wang-Kong Tse , S. Das Sarma

We show that plasmons in two-dimensional graphene can have net gain at terahertz frequencies. The coupling of the plasmons to interband electron-hole transitions in population inverted graphene layers can lead to plasmon amplification…

Mesoscale and Nanoscale Physics · Physics 2007-06-13 Farhan Rana , Faisal R. Ahmad

Using the first principles calculations, we show that mechanically tunable electronic energy gap is realizable in bilayer graphene if different homogeneous strains are applied to the two layers. It is shown that the size of energy gap can…

Mesoscale and Nanoscale Physics · Physics 2010-09-13 Seon-Myeong Choi , Seung-Hoon Jhi , Young-Woo Son

Two-dimensional (2D) materials have recently been the focus of extensive research. By following a similar trend as graphene, other 2D materials including transition metal dichalcogenides (MX2) and metal mono-chalcogenides (MX) show great…

In graphene devices, the electronic drift velocity can easily exceed the speed of sound in the material at moderate current biases. Under this condition, the electronic system can efficiently amplify acoustic phonons, leading to the…