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Related papers: Infrared spectroscopy of electronic bands in bilay…

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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

A tight binding model is used to calculate the band structure of bilayer graphene in the presence of a potential difference between the layers that opens a gap $\Delta$ between the conduction and valence bands. In particular, a self…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Edward McCann

Van der Waals heterostructures obtained by artificially stacking two-dimensional crystals represent the frontier of material engineering, demonstrating properties superior to those of the starting materials. Fine control of the interlayer…

Detection of infrared light is central to diverse applications in security, medicine, astronomy, materials science, and biology. Often different materials and detection mechanisms are employed to optimize performance in different spectral…

Mesoscale and Nanoscale Physics · Physics 2012-07-03 J. Yan , M. -H. Kim , J. A. Elle , A. B. Sushkov , G. S. Jenkins , H. M. Milchberg , M. S. Fuhrer , H. D. Drew

We study the electronic properties of twisted bilayers graphene in the tight-binding approximation. The interlayer hopping amplitude is modeled by a function, which depends not only on the distance between two carbon atoms, but also on the…

Mesoscale and Nanoscale Physics · Physics 2015-08-12 A. O. Sboychakov , A. L. Rakhmanov , A. V. Rozhkov , Franco Nori

We present a theoretical study of the local optical conductivity, plasmon spectra, and thermoelectric properties of twisted bilayer graphene (TBG) at different filling factors and twist angles $\theta$. Our calculations are based on the…

Mesoscale and Nanoscale Physics · Physics 2020-09-04 Pietro Novelli , Iacopo Torre , Frank H. L. Koppens , Fabio Taddei , Marco Polini

We use temperature-dependent resistivity in small-angle twisted double bilayer graphene to measure bandwidths and gaps of the bands. This electron-hole asymmetric system has one set of non-dispersing bands that splits into two flat bands…

We describe the gated bilayer graphene system when it is subjected to intense terahertz frequency electromagnetic radiation. We examine the electron band structure and density of states via exact diagonalization methods within Floquet…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 D. S. L. Abergel , Tapash Chakraborty

Bilayer graphene is normally a semimetal with parabolic dispersion, but a tunable bandgap up to few hundreds meV can be opened by breaking the symmetry between the layers through an external potential. Ab-initio calculations show that the…

Mesoscale and Nanoscale Physics · Physics 2015-09-30 Simone De Liberato

The absorption of heavily doped graphene in the terahertz (THz) and mid-infrared (MIR) spectral regions is considered taking into account both the elastic scattering due to finite-range disorder and the variations of concentration due to…

Materials Science · Physics 2015-06-11 F. T. Vasko , V. V. Mitin , V. Ryzhii , T. Otsuji

Twisted bilayer graphene (tBLG) devices with ion gel gate dielectrics are studied using Raman spectroscopy in the twist angle regime where a resonantly enhanced G band can be observed. We observe prominent splitting and intensity quenching…

Mesoscale and Nanoscale Physics · Physics 2015-02-18 Ting-Fung Chung , Rui He , Tai-Lung Wu , Yong P. Chen

A perpendicular electric field breaks the layer symmetry of Bernal-stacked bilayer graphene, resulting in the opening of a band gap and a modification of the effective mass of the charge carriers. Using scanning tunneling microscopy and…

The interlayer coupling of twisted bilayer graphene could markedly affect its electronic band structure. A current challenge required to overcome in experiment is how to precisely control the coupling and therefore tune the electronic…

Mesoscale and Nanoscale Physics · Physics 2012-08-07 Lan Meng , Wei Yan , Zhao-Dong Chu , Yanfeng Zhang , Lei Feng , Rui-Fen Dou , Jia-Cai Nie , Lin He

Flatbands with extremely narrow bandwidths on the order of a few mili-electron volts can appear in twisted multilayer graphene systems for appropriate system parameters. Here we investigate the electronic structure of a twisted bi-bilayer…

Mesoscale and Nanoscale Physics · Physics 2019-06-24 Narasimha Raju Chebrolu , Bheema Lingam Chittari , Jeil Jung

In this work we study the behavior of the optical phonon modes in bilayer graphene devices by applying top gate voltage, using Raman scattering. We observe the splitting of the Raman G band as we tune the Fermi level of the sample, which is…

Mesoscale and Nanoscale Physics · Physics 2012-06-07 D. L. Mafra , P. Gava , L. M. Malard , R. S. Borges , G. G. Silva , J. A. Leon , F. Plentz , F. Mauri , M. A. Pimenta

The electronic band structure of twisted bilayer graphene develops van Hove singularities whose energy depends on the twist angle between the two layers. Using Raman spectroscopy, we monitor the evolution of the electronic band structure…

The unique property of bilayer graphene to show a band gap tunable by external electrical fields enables a variety of different device concepts with novel functionalities for electronic, optoelectronic and sensor applications. So far the…

Materials Science · Physics 2016-09-21 Bartholomaeus N. Szafranek , Daniel Schall , Martin Otto , Daniel Neumaier , Heinrich Kurz

The band structure of Bernal-stacked bilayer graphene can be tuned using double-gated transistors to apply a perpendicular electric field that generates an interlayer potential energy difference $\Delta$. Dielectric breakdown limits the…

Mesoscale and Nanoscale Physics · Physics 2026-01-28 Margherita Melegari , Brian Skinner , Ignacio Gutierrez-Lezama , Alberto F. Morpurgo

We present an experimental study of the infrared conductivity, transmission, and reflection of a gated bilayer graphene and their theoretical analysis within the Slonczewski-Weiss-McClure (SWMc) model. The infrared response is shown to be…

Mesoscale and Nanoscale Physics · Physics 2008-12-04 L. M. Zhang , Z. Q. Li , D. N. Basov , M. M. Fogler , Z. Hao , M. C. Martin

Twisted bilayer graphene with a twist angle of around 1.1{\deg} features a pair of isolated flat electronic bands and forms a strongly correlated electronic platform. Here, we use scanning tunneling microscopy to probe local properties of…