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Related papers: Chirality-induced Dynamic Kohn Anomalies in Graphe…

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Kohn anomalies in three-dimensional metallic crystals are dips in the phonon dispersion that are caused by abrupt changes in the screening of the ion-cores by the surrounding electron-gas. These anomalies are also present at the…

Mesoscale and Nanoscale Physics · Physics 2013-11-19 F. Forster , A. Molina-Sanchez , S. Engels , A. Epping , K. Watanabe , T. Taniguchi , L. Wirtz , C. Stampfer

Recent advances in strain engineering at the nanoscale have shown the feasibility to modulate the properties of graphene. Although the electron-phonon (e-ph) coupling and Kohn anomalies in graphene define the phonon branches contributing to…

Mesoscale and Nanoscale Physics · Physics 2016-08-02 M. E. Cifuentes-Quintal , O. de la Peña-Seaman , R. Heid , R. de Coss , K. -P. Bohnen

We demonstrate that graphite phonon dispersions have two Kohn anomalies at the Gamma-E_2g and K-A'1 modes. The anomalies are revealed by two sharp kinks. By an exact analytic derivation, we show that the slope of these kinks is proportional…

Materials Science · Physics 2010-09-03 S. Piscanec , M. Lazzeri , F. Mauri , A. C. Ferrari , J. Robertson

The phonon dispersion of graphene on Ir(111) has been determined by means of angle-resolved inelastic electron scattering and density functional calculations. Kohn anomalies of the highest optical-phonon branches are observed at the…

Materials Science · Physics 2015-06-17 M. Endlich , A. Molina-Sánchez , L. Wirtz , J. Kröger

The dispersion of electrons and phonons near the K point of bilayer graphene was investigated in a resonant Raman study using different laser excitation energies in the near infrared and visible range. The electronic structure was analyzed…

Mesoscale and Nanoscale Physics · Physics 2011-04-08 D. L. Mafra , L. M. Malard , S. K. Doorn , H. Htoon , J. Nilsson , A. H. Castro Neto , M. A. Pimenta

Phonon dispersions generically display non-analytic points, known as Kohn anomalies, due to electron-phonon interactions. We analyze this phenomenon for a zone boundary phonon in undoped graphene. When electron-electron interactions with…

Strongly Correlated Electrons · Physics 2012-03-22 Fernando de Juan , Herbert A. Fertig

In neutral graphene, two prominent cusps known as Kohn anomalies are found in the phonon dispersion of the highest optical phonon at $q=\Gamma$ (LO branch) and $q=K$ (TO branch), reflecting a significant electron-phonon coupling to undoped…

Mesoscale and Nanoscale Physics · Physics 2015-08-18 Antonio Politano , Fernando de Juan , Gennaro Chiarello , Herbert A. Fertig

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

The interaction of electron-hole pairs with lattice vibrations exhibits a wealth of intriguing physical phenomena. The Kohn anomaly is a renowned example where electron-phonon coupling leads to non-analytic phonon dispersion at specific…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Jun Yan , Erik A. Henriksen , Philip Kim , Aron Pinczuk

The two-dimensional mapping of the phonon dispersions around the $K$ point of graphite by inelastic x-ray scattering is provided. The present work resolves the longstanding issue related to the correct assignment of transverse and…

Strongly Correlated Electrons · Physics 2015-05-13 A. Grüneis , J. Serrano , A. Bosak , M. Lazzeri , S. L. Molodtsov , L. Wirtz , C. Attaccalite , M. Krisch , A. Rubio , F. Mauri , T. Pichler

Twisted bilayer graphene (TBG) has attracted great interest in the last decade due to the novel properties it exhibited. It was revealed that e-phonon interaction plays an important role in a variety of phenomena in this system, such as…

Mesoscale and Nanoscale Physics · Physics 2024-10-29 Jun-Wei Li , Jia-Xing Zhang , Wei Chen

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

The interplay of electron-phonon (el-ph) and electron-electron (el-el) interactions in epitaxial graphene is studied by directly probing its electronic structure. We found a strong coupling of electrons to the soft part of the A1g phonon…

Materials Science · Physics 2008-11-21 S. Y. Zhou , D. A. Siegel , A. V. Fedorov , A. Lanzara

A theoretical investigation of the possible existence of the chiral polaron formation in graphene is reported. We present an analytical method to calculate the ground-state of the electron-phonon system within the framework of the Lee-Low…

Mesoscale and Nanoscale Physics · Physics 2019-07-09 B. S. Kandemir

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

One of the unique properties of graphene is its extremely high mechanical strength. Several studies have shown that the mechanical failure of graphene sheet under a tensile strain is due to the enhancement of the Kohn anomaly of the zone…

Mesoscale and Nanoscale Physics · Physics 2018-09-19 Sonia Haddad , Lassaad Mandhour

Breaking the intrinsic chirality of quasiparticles in graphene enables the emergence of new and intriguing phases. One such paradigmatic example is the bond density wave, which leads to a Kekul\'{e}-ordered structure and underpins exotic…

Mesoscale and Nanoscale Physics · Physics 2025-06-23 Dominik Szczȩśniak

Motivated to understand the phonon spectrum renormalization in the ground state of the half-filled SSH model, we use the Born-Oppenheimer approximation together with the harmonic approximation to evaluate the all-to-all real-space ionic…

Strongly Correlated Electrons · Physics 2021-10-04 Stepan Fomichev , Mona Berciu

Electron-phonon interaction and related self-energy are fundamental to both the equilibrium properties and non-equilibrium relaxation dynamics of solids. Although electron-phonon interaction has been suggested by various time-resolved…

Mesoscale and Nanoscale Physics · Physics 2023-05-09 Hongyun Zhang , Changhua Bao , Michael Schüler , Shaohua Zhou , Qian Li , Laipeng Luo , Wei Yao , Zhong Wang , Thomas P. Devereaux , Shuyun Zhou

Cyclotron resonance in bilayer graphene is studied with weak electron-hole asymmetry, suggested by experiment, taken into account and with the focus on many-body corrections that evade Kohn's theorem. It is shown by direct calculation that…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 K. Shizuya
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