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Related papers: Tunable Excitons in Biased Bilayer Graphene

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Excitonic bound states are characterised by a binding energy $\epsilon_b$ and a single-particle band gap $\Delta_b$. This work provides a theoretical description for both strong ($\epsilon_b\sim\Delta_b$) and weak ($\epsilon_b\ll\Delta_b$)…

Strongly Correlated Electrons · Physics 2023-02-22 Harley D. Scammell , Oleg P. Sushkov

Recently the small-twist-angle (< 2{\deg}) bilayer graphene has received extraordinary attentions due to its exciting physical properties. Compared with monolayer graphene, the Brillouin zone folding in twisted bilayer graphene (TBG) leads…

Mesoscale and Nanoscale Physics · Physics 2020-12-24 Bingchen Deng , Chao Ma , Qiyue Wang , Shaofan Yuan , Kenji Watanabe , Takashi Taniguchi , Fan Zhang , Fengnian Xia

We study, within the tight-binding approximation, the electronic properties of a graphene bilayer in the presence of an external electric field applied perpendicular to the system -- \emph{biased bilayer}. The effect of the perpendicular…

We present ab initio many-body calculations of the optical absorption in bulk graphite, graphene and bilayer of graphene. Electron-hole interaction is included solving the Bethe-Salpeter equation on top of a GW quasiparticle electronic…

Materials Science · Physics 2015-05-14 Paolo E. Trevisanutto , Markus Holzmann , Michel Cote , Valerio Olevano

Owing to the interaction between the layers, the twisted bilayer two-dimensional materials exhibit numerous unique optical and electronic properties different from the monolayer counterpart, and have attracted tremendous interests in…

Mesoscale and Nanoscale Physics · Physics 2021-08-18 Yabin Ma , Tao Ouyang , Yuanping Chen , Yuee Xie

Bilayer graphene has many unique optoelectronic properties , including a tuneable band gap, that make it possible to develop new and more efficient optical and nanoelectronic devices. We have developed a Monte Carlo simulation for a single…

Mesoscale and Nanoscale Physics · Physics 2015-07-20 J. O. D. Williams , J. S. Lapington , M. Roy , I. B. Hutchinson

The electronic structure and optical response of electrically gated bilayer graphene are studied by first-principles approaches. We have obtained the induced band gap that is in good agreement with experiment when the applied electric field…

Mesoscale and Nanoscale Physics · Physics 2015-03-13 Li Yang

It has been predicted that application of a strong electric field perpendicular to the plane of bilayer graphene can induce a significant band gap. We have measured the optical conductivity of bilayer graphene with an efficient electrolyte…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Kin Fai Mak , Chun Hung Lui , Jie Shan , Tony F. Heinz

Common wisdom asserts that bound excitons cannot form in high-dimensional (d>1) metallic structures because of their overwhelming screening and unavoidable resonance with nearby continuous bands. Strikingly, here we illustrate that this…

Mesoscale and Nanoscale Physics · Physics 2014-09-29 Yufeng Liang , Ryan Soklaski , Shouting Huang , Matthew W. Graham , Robin Havener , Jiwoong Park , Li Yang

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

The tight-binding model of bilayer graphene is used to find the gap between the conduction and valence bands, as a function of both the gate voltage and as the doping by donors or acceptors. The total Hartree energy is minimized and the…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 L. A. Falkovsky

We have studied temperature dependences of electron transport in graphene and its bilayer and found extremely low electron-phonon scattering rates that set the fundamental limit on possible charge carrier mobilities at room temperature. Our…

Mesoscale and Nanoscale Physics · Physics 2008-01-07 S. V. Morozov , K. S. Novoselov , M. I. Katsnelson , F. Schedin , D. C. Elias , J. A. Jaszczak , A. K. Geim

For graphene to be utilized in the digital electronics industry the challenge is to create bandgaps of order 1eV as simply as possible. The most successful methods for the creation of gaps in graphene are (a) confining the electrons in…

Mesoscale and Nanoscale Physics · Physics 2014-03-13 A. R. Davenport , J. P. Hague

We explore the device potential of tunable-gap bilayer graphene FET exploiting the possibility of opening a bandgap in bilayer graphene by applying a vertical electric field via independent gate operation. We evaluate device behavior using…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 G. Fiori , G. Iannaccone

We present atomistic calculations on structural and electronic properties of twisted double bilayer graphene (TDBG) consisting of two sets of rotationally misaligned Bernal-stacked bilayer graphene. Obtained equilibrium atomic structures…

Mesoscale and Nanoscale Physics · Physics 2019-11-20 Young Woo Choi , Hyoung Joon Choi

We discuss the physics of the tunable bandgap in bilayer graphene with the gate voltage and doping. A comparison with experimental data obtained by Kuzmenko et al [Phys. Rev. B \textbf{80}, 165406 (2009)] demonstrates the good agreement.

Mesoscale and Nanoscale Physics · Physics 2010-11-29 L. A. Falkovsky

Moir\'e excitons are emergent optical excitations in 2D semiconductors with deep moir\'e superlattice potentials. While these excitations have been realized in several platforms, a system with dynamically tunable moir\'e potential to tailor…

Bilayer graphene is a highly promising material for electronic and optoelectronic applications since it is supporting massive Dirac fermions with a tuneable band gap. However, no consistent picture of the gap's effect on the optical and…

In this work, we investigate the intrinsic limits of subthreshold slope in a dual gated bilayer graphene transistor using a coupled self-consistent Poisson-bandstructure solver. We benchmark the solver by matching the bias dependent bandgap…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Kausik Majumdar , Kota V. R. M. Murali , Navakanta Bhat , Yu-Ming Lin

The large tunability of band gaps and optical absorptions of armchair MoS$_2$ nanoribbons of different widths under bending is studied using density functional theory and many-body perturbation GW and Bethe-Salpeter equation approaches. We…

Computational Physics · Physics 2022-11-02 Hong Tang , Bimal Neupane , Santosh Neupane , Shiqi Ruan , Niraj K. Nepal , Adrienn Ruzsinszky