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The active photonics based on the two-dimensional material graphene has attracted enormous interests for developing the tunable and compact optical devices with high efficiency. Here we integrate graphene into the Fano-resonant…

We report on resonance Raman spectroscopy measurements with excitation photon energy down to 1.16 eV on graphene, to study how low-energy carriers interact with lattice vibrations. Thanks to the excitation energy close to the Dirac point at…

Efficient conversion of electrical signal to optical signal in nano-photonics enables solid state integration of electronics and photonics. Combination of graphene with photonic crystals is promising for electro-optic modulation. In this…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 Arka Majumdar , Jonghwan Kim , Jelena Vuckovic , Feng Wang

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 paper we give a striking theoretical example of such materials design: a tunable gap in…

Mesoscale and Nanoscale Physics · Physics 2013-04-29 Thomas Iadecola , David Campbell , Claudio Chamon , Chang-Yu Hou , Roman Jackiw , So-Young Pi , Silvia Viola Kusminskiy

Graphene phonons are measured as a function of electron doping via the addition of potassium adatoms. In the low doping regime, the in-plane carbon G-peak hardens and narrows with increasing doping, analogous to the trend seen in graphene…

Mesoscale and Nanoscale Physics · Physics 2015-03-17 C. A. Howard , M. P. M. Dean , F. Withers

Suspended graphene exhibits ripples of size ranging from 50 to 100 {\AA} and height $\sim$10{\AA}, however, their origin remains undetermined. Previous theoretical works have proposed that rippling in graphene might be generated by the…

Mesoscale and Nanoscale Physics · Physics 2020-07-08 Tommaso Cea , Miguel Ruiz-Garcia , Luis Bonilla , Francisco Guinea

The role of electron-phonon interactions is experimentally and theoretically investigated near the saddle point absorption peak of graphene. The differential optical transmission spectra of multiple, non-interacting layers of graphene…

We observe a giant increase of the infrared intensity and a softening of the in-plane antisymmetric phonon mode Eu (~0.2 eV) in bilayer graphene as a function of the gate-induced doping. The phonon peak has a pronounced Fano-like asymmetry.…

Strongly Correlated Electrons · Physics 2015-05-13 A. B. Kuzmenko , L. Benfatto , E. Cappelluti , I. Crassee , D. van der Marel , P. Blake , K. S. Novoselov , A. K. Geim

We study the effect exerted by the electrons on the flexural phonons in graphene, accounting for the attractive interaction created by the exchange of electron-hole excitations. Combining the self-consistent computation of the phonon…

Mesoscale and Nanoscale Physics · Physics 2010-03-18 Pablo San-Jose , Jose González , Francisco Guinea

Bandgaps in layered materials are critical for enabling functionalities such as tunable photodetection, efficient energy conversion, and nonlinear optical responses, which are essential for next-generation photonic and quantum devices. Gap…

Inelastic electron tunneling provides a low-energy pathway for the excitation of surface plasmons and light emission. We theoretically investigate tunnel junctions based on metals and graphene. We show that graphene is potentially a highly…

Mesoscale and Nanoscale Physics · Physics 2015-08-28 Kelvin J. A. Ooi , Hong Son Chu , Chang Yu Hsieh , Dawn T. H. Tan , Lay Kee Ang

Using first-principles full-potential density functional calculations, we predict that mechanically tunable band-gap is realizable in ZnS monolayer in graphene-like honeycomb structure by application of in-plane homogeneous biaxial strain.…

Materials Science · Physics 2012-10-12 Harihar Behera , Gautam Mukhopadhyay

The zero gap electronic bands in the monolayer graphene are shown to be unstable relative to the dynamic symmetry violation due to the electron-phonon interaction.

Mesoscale and Nanoscale Physics · Physics 2009-10-20 Sergey A. Ktitorov , Xiaoxing Chen

Growth of graphene on monolayer transition-metal dichalcogenides presents opening on band gap and giant spin-orbit coupling which paves the way to achieve a useful hybrid structure for electronics and spintronics applications. Increase of…

Mesoscale and Nanoscale Physics · Physics 2019-01-29 S. F. Ebadzadeh , H. Goudarzi , M. Khezerlou

Graphene- the wonder material has attracted a great deal of attention from varied fields of condensed matter physics, materials science and chemistry in recent times. Its 2D atomic layer structure and unique electronic band structure makes…

Materials Science · Physics 2011-08-23 Deep Jariwala , Anchal Srivastava , Pulickel Ajayan

We report a comprehensive study of the tuning with electric fields of the resonant magneto-exciton optical phonon coupling in gated graphene. For magnetic fields around $B \sim 25$ T which correspond to the range of the fundamental…

Mesoscale and Nanoscale Physics · Physics 2014-05-14 P. Leszczynski , Z. Han , A. A. L. Nicolet , B. A. Piot , P. Kossacki , M. Orlita , V. Bouchiat , D. M. Basko , M. Potemski , C. Faugeras

We show that the electron-phonon coupling in graphene, in contrast with the non-relativistic two-dimensional electron gas, leads to shifts in the phonon frequencies that are non-trivial functions of the electronic density. These shifts can…

Strongly Correlated Electrons · Physics 2013-05-29 A. H. Castro Neto , Francisco Guinea

Periodic structures with subwavelength features are instrumental in the versatile and effective control of electromagnetic waves from radio frequencies up to optics. In this paper, we theoretically evaluate the potential applications and…

Mesoscale and Nanoscale Physics · Physics 2013-01-04 Arya Fallahi , Julien Perruisseau-Carrier

The efficiency of optical emitters can be dramatically enhanced by reducing the effective mode volume (the Purcell effect). Here we predict an analogous enhancement for electron-phonon (el-ph) scattering, achieved by compressing the…

Mesoscale and Nanoscale Physics · Physics 2021-11-18 Hiroaki Ishizuka , Ali Fahimniya , Francisco Guinea , Leonid Levitov

We achieve fine tuning of graphene effective doping by applying ultrahigh pressures (> 10 GPa) using Atomic Force Microscopy (AFM) diamond tips. Specific areas in graphene flakes are irreversibly flattened against a SiO2 substrate. Our work…