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Related papers: Quantum-criticality in twisted bi-layer graphene

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The discovery of superconductivity in twisted bilayer and twisted trilayer graphene has generated tremendous interest. The key feature of these systems is an interplay between interlayer coupling and a moir\'e superlattice that gives rise…

We employ dual-gated 30{\deg}-twisted bilayer graphene to demonstrate simultaneous ultra-high mobility and conductivity (up to 40 mS at room temperature), unattainable in a single-layer of graphene. We find quantitative agreement with a…

Mesoscale and Nanoscale Physics · Physics 2022-01-12 Giulia Piccinini , Vaidotas Mišeikis , Kenji Watanabe , Takashi Taniguchi , Camilla Coletti , Sergio Pezzini

Flat-band systems are a promising platform for realizing exotic collective ground states with spontaneously broken symmetry because the electron-electron interactions dominate over the kinetic energy. A collective ground state of particular…

Mesoscale and Nanoscale Physics · Physics 2022-04-20 Xiang Hu , Timo Hyart , Dmitry I. Pikulin , Enrico Rossi

Twisted van der Waals materials have been shown to host a variety of tunable electronic structures. Here we put forward twisted trilayer graphene (TTG) as a platform to emulate heavy fermion physics. We demonstrate that TTG hosts extended…

Mesoscale and Nanoscale Physics · Physics 2021-07-08 Aline Ramires , Jose L. Lado

Flat band electronic modes are responsible for superconductivity in twisted bilayer graphene (TBG) rotated at magic angles. From there other magic angles can be found for any multilayered twisted graphene systems. Eventually, this lead to…

Mesoscale and Nanoscale Physics · Physics 2022-12-15 Leonardo A. Navarro-Labastida , Gerardo G. Naumis

The rich phenomenology of twisted bilayer graphene (TBG) near the magic angle is believed to arise from electron correlations in topological flat bands. An unbiased approach to this problem is highly desirable, but also particularly…

Strongly Correlated Electrons · Physics 2021-09-28 Johannes S. Hofmann , Eslam Khalaf , Ashvin Vishwanath , Erez Berg , Jong Yeon Lee

We propose an SU(4) spin-valley-fermion model to investigate the superconducting instabilities of twisted bilayer graphene (TBG). In this approach, bosonic fluctuations associated with an emergent SU(4) symmetry, corresponding to combined…

Superconductivity · Physics 2021-01-20 Yuxuan Wang , Jian Kang , Rafael M. Fernandes

Strongly interacting electrons in solid-state systems often display tendency towards multiple broken symmetries in the ground state. The complex interplay between different order parameters can give rise to a rich phase diagram. Here, we…

Magic-angle twisted bilayer graphene exhibits quasi-flat low-energy bands with Van Hove singularities close to the Fermi level. These singularities play an important role in the exotic phenomena observed in this material, such as…

Mesoscale and Nanoscale Physics · Physics 2022-12-08 Aleksander Sanjuan Ciepielewski , Jakub Tworzydło , Timo Hyart , Alexander Lau

Many of the experiments in twisted bilayer graphene (TBG) differ from each other in terms of the details of their phase diagrams. Few controllable aspects aside, this discrepancy is largely believed to be arising from the presence of a…

Mesoscale and Nanoscale Physics · Physics 2020-09-30 Bikash Padhi , Apoorv Tiwari , Titus Neupert , Shinsei Ryu

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 double bilayer graphene is a compensated semi-metal near the charge neutrality point with the presence of small electron and hole pockets in its band structure. We show that strong Coulomb attraction between the electrons and holes…

Strongly Correlated Electrons · Physics 2023-07-26 Unmesh Ghorai , Ayan Ghosh , Anindya Das , Rajdeep Sensarma

Staking layered materials revealed to be a very powerful method to tailor their electronic properties. It has indeed been theoretically and experimentally shown that twisted bilayers of graphene (tBLG) with a rotation angle $\theta$,…

Mesoscale and Nanoscale Physics · Physics 2020-07-01 Omid Faizy Namarvar , Ahmed Missaoui , Laurence Magaud , Didier Mayou , Guy Trambly de Laissardière

Magic-angle ($\theta=1.05^\circ$) twisted bilayer graphene (MATBG) has shown two seemingly contradictory characters: the localization and quantum-dot-like behavior in STM experiments, and delocalization in transport experiments. We…

Strongly Correlated Electrons · Physics 2023-01-12 Zhi-Da Song , B. Andrei Bernevig

Using a combined Dynamical Mean Field Theory and Hartree (DMFT+H) calculation we study the transport and optical properties of the 8-band heavy fermion model for Twisted Bilayer Graphene (TBG) in the normal state. We find resistive states…

Strongly Correlated Electrons · Physics 2026-05-19 M. J. Calderón , A. Camjayi , A. Datta , E. Bascones

We study the interacting transport properties of twisted bilayer graphene (TBG) using the topological heavy-fermion (THF) model. In the THF model, TBG comprises localized, correlated $f$-electrons and itinerant, dispersive $c$-electrons. We…

Strongly Correlated Electrons · Physics 2024-02-23 Dumitru Călugăru , Haoyu Hu , Rafael Luque Merino , Nicolas Regnault , Dmitri K. Efetov , B. Andrei Bernevig

The understanding of strongly-correlated materials, and in particular unconventional superconductors, has puzzled physicists for decades. Such difficulties have stimulated new research paradigms, such as ultra-cold atom lattices for…

Mesoscale and Nanoscale Physics · Physics 2018-05-22 Yuan Cao , Valla Fatemi , Shiang Fang , Kenji Watanabe , Takashi Taniguchi , Efthimios Kaxiras , Pablo Jarillo-Herrero

The unexpected discovery of superconductivity and strong electron correlation in twisted bilayer graphene (TBG), a system containing only sp electrons, is considered as one of the most intriguing developments in two-dimensional materials in…

Mesoscale and Nanoscale Physics · Physics 2025-04-22 Wei-Chen Wang , Feng-Wu Chen , Kuan-Sen Lin , Justin T. Hou , Ho-Chun Lin , Mei-Yin Chou

Recent experimental study unveiled highly unconventional phenomena in the superconducting twisted bilayer graphene (TBG) with ultra flat bands, which cannot be described by the conventional BCS theory. For example, given the small Fermi…

Superconductivity · Physics 2024-02-05 Shuai A. Chen , K. T. Law

We investigate electronic transport in twisted bilayer graphene (tBLG) under variable temperatures ($T$), carrier densities ($n$), and transverse magnetic fields, focusing on samples with small-twist-angles ($\theta$). These samples show…

Mesoscale and Nanoscale Physics · Physics 2018-08-24 Ting-Fung Chung , Yang Xu , Yong P. Chen