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Related papers: Dynamic Kohn anomaly in twisted bilayer graphene

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Magic-Angle Twisted Bilayer Graphene shows a wide range of correlated phases which are electrostatically tunable. Despite a growing knowledge of the material, there is yet no consensus on the microscopic mechanisms driving its…

Twisted bilayer graphene (tBLG) provides us with a large rotational freedom to explore new physics and novel device applications, but many of its basic properties remain unresolved. Here we report the synthesis and systematic Raman study of…

The origin of superconductivity in twisted bilayer graphene -- whether phonon-driven or electron-driven -- remains unresolved, in part due to the absence of a quantitative and efficient model for electron-phonon coupling (EPC). In this…

Mesoscale and Nanoscale Physics · Physics 2026-02-12 Ziyan Zhu , Thomas P. Devereaux

We investigate the domain wall network in twisted bilayer graphene (TBG) under the influence of interlayer bias and screening effect from the layered structure. Starting from the continuum model, we analyze the low-energy domain wall modes…

Mesoscale and Nanoscale Physics · Physics 2024-07-22 Hao-Chien Wang , Chen-Hsuan Hsu

Recent research on twisted bilayer graphene (TBG) uncovered that its twist-angle-dependent electronic structure leads to a host of unique properties, such as superconductivity, correlated insulating states, and magnetism. The flat bands…

Mesoscale and Nanoscale Physics · Physics 2021-03-29 Adithya Kommini , Zlatan Aksamija

Recent experiments on twisted bilayer graphene (tBG) close to magic angle show that a small relative rotation in a van der Waals heterostructure greatly alters its electronic properties. We consider various scattering mechanisms and show…

Mesoscale and Nanoscale Physics · Physics 2019-04-24 I. Yudhistira , N. Chakraborty , G. Sharma , D. Y. H. Ho , E. Laksono , O. P. Sushkov , G. Vignale , S. Adam

Lattice dynamics play a crucial role in the physics of Moir\'e systems. In twisted bilayer graphene (TBG), it was shown that, in addition to the graphene phonons, there is another set of gapless excitations termed Moir\'e Phonons [Phys.…

Mesoscale and Nanoscale Physics · Physics 2022-08-23 Qiang Gao , Eslam Khalaf

We show that the recently observed superconductivity in twisted bilayer graphene (TBG) can be explained as a consequence of the Kohn-Luttinger (KL) instability which leads to an effective attraction between electrons with originally…

Mesoscale and Nanoscale Physics · Physics 2019-01-21 J. González , T. Stauber

Twisted bilayer graphene (TBG) near the magic twist angle of $\sim1.1^{o}$ exhibits a rich phase diagram. However, the interplay between different phases and their dependence on twist angle is still elusive. Here, we explore the stability…

In this work we carry out a theoretical study of the phonon-induced resistivity in twisted double bilayer graphene (TDBG), in which two Bernal-stacked bilayer graphene devices are rotated relative to each other by a small angle $\theta$. We…

Strongly Correlated Electrons · Physics 2020-06-30 Xiao Li , Fengcheng Wu , S. Das Sarma

In this work, we present a theoretical research on the lattice relaxations, phonon properties, and relaxed electronic structures in magic-angle twisted bilayer graphene (TBG). We construct a continuum elastic model in order to study the…

Mesoscale and Nanoscale Physics · Physics 2024-01-30 Bo Xie , Jianpeng Liu

We develop a theoretical framework for probing moir\'e phonon modes using Raman spectroscopy, and illustrate it with the example of twisted bilayer graphene (TBG). These moir\'e phonons arise from interlayer sliding motion in twisted 2D…

Strongly Correlated Electrons · Physics 2025-06-24 Vitor Dantas , Héctor Ochoa , Rafael M. Fernandes , Natalia B. Perkins

Moir\'e materials, and in particular twisted bilayer graphene (TBG), exhibit a range of fascinating phenomena, that emerge from the interplay of band topology and interactions. We show that the non-linear second-order photoresponse is an…

Mesoscale and Nanoscale Physics · Physics 2021-07-21 Swati Chaudhary , Cyprian Lewandowski , Gil Refael

The coupling between electrons and phonons is one of the fundamental interactions in solids, underpinning a wide range of phenomena such as resistivity, heat conductivity, and superconductivity. However, direct measurements of this coupling…

Charge-neutral conducting systems represent a class of materials with unusual properties governed by electron-hole (e-h) interactions. Depending on the quasiparticles' statistics, band structure, and device geometry these semimetallic…

Mesoscale and Nanoscale Physics · Physics 2023-03-23 D. A. Bandurin , A. Principi , I. Y. Phinney , T. Taniguchi , K. Watanabe , P. Jarillo-Herrero

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

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

Twisted bilayer graphene (TBG) has taken the spotlight in the condensed matter community since the discovery of correlated phases at the so-called magic angle. Interestingly, the role of a substrate on the electronic properties of TBG has…

Mesoscale and Nanoscale Physics · Physics 2022-04-26 Min Long , Pierre A. Pantaleón , Zhen Zhan , Francisco Guinea , Jose Ángel Silva-Guillén , Shengjun Yuan

Twisted 2D layered materials have garnered a lot of attention recently as a class of 2D materials whose interlayer interactions and electronic properties are dictated by the relative rotation / twist angle between the adjacent layers. In…

Identifying the microscopic processes that limit conductivity is essential for understanding correlated and quantum-critical states in quantum materials. In twisted bilayer graphene (TBG) and other twist-controlled materials, the…