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Related papers: Molecular Pairing in Twisted Bilayer Graphene Supe…

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We study the effect of electron-acoustic phonon interactions in twisted bilayer graphene on resistivity in the high-temperature transport and superconductivity in the low-temperature phase diagram. We theoretically show that twisted bilayer…

Mesoscale and Nanoscale Physics · Physics 2019-04-10 Fengcheng Wu , Euyheon Hwang , Sankar Das Sarma

Magic-angle twisted bilayer graphene (MATBG) hosts normal-state nearly-flat bands with nonzero Euler numbers and shows superconductivity. In this work, we study the effects of the nontrivial normal-state band topology on the intervalley…

Superconductivity · Physics 2025-01-03 Jiabin Yu , Ming Xie , Fengcheng Wu , Sankar Das Sarma

Graphene moire superlattices are outstanding platforms to study correlated electron physics and superconductivity with exceptional tunability. However, robust superconductivity has been measured only in magic-angle twisted bilayer graphene…

Mesoscale and Nanoscale Physics · Physics 2021-10-20 Young Woo Choi , Hyoung Joon Choi

We investigate the competition between acoustic-phonon-mediated superconductivity and the long-range Coulomb interaction in moir\'eless graphene multilayers, specifically, Bernal bilayer graphene, rhombohedral trilayer graphene, and…

Superconductivity · Physics 2022-07-11 Yang-Zhi Chou , Fengcheng Wu , Jay D. Sau , Sankar Das Sarma

We studied the real space structure of states in twisted bilayer graphene at the `magic angle' $\theta = 1.08^\circ$. The flat bands close to charge neutrality are composed of a mix of `ring' and `center' orbitals around the AA stacking…

Strongly Correlated Electrons · Physics 2019-01-02 Louk Rademaker , Paula Mellado

A remarkable recent experiment has observed Mott insulator and proximate superconductor phases in twisted bilayer graphene when electrons partly fill a nearly flat mini-band that arises a `magic' twist angle. However, the nature of the Mott…

Strongly Correlated Electrons · Physics 2018-10-03 Hoi Chun Po , Liujun Zou , Ashvin Vishwanath , T. Senthil

Unconventional superconductivity often arises from Cooper pairing between neighboring atomic sites, stipulating a characteristic pairing symmetry in the reciprocal space. The twisted bilayer graphene (TBG) presents a new setting where…

Superconductivity · Physics 2019-07-15 Sujay Ray , Jeil Jung , Tanmoy Das

We show that introducing spin-singlet or spin-triplet superconductivity into twisted bilayer graphene induces higher-order topological superconductivity. $C_{2z}T$-protected corner states of Majorana Kramers pairs appear at the boundary…

Superconductivity · Physics 2021-08-13 Aaron Chew , Yijie Wang , B. Andrei Bernevig , Zhi-Da Song

We report strong electron-phonon coupling in magic-angle twisted bilayer graphene (MA-TBG) obtained from atomistic description of the system including more than 10000 atoms in the moire supercell. Electronic structure, phonon spectrum, and…

Mesoscale and Nanoscale Physics · Physics 2018-12-27 Young Woo Choi , Hyoung Joon Choi

`More is Different' (Anderson, 1972) in graphene. A bilayer and a twist spring surprises. Recently discovered superconductivity (T$_c\approx$ 1.7 K) at an ultra low doping density $\sim 10^{11}$cm${}^{-2}$ has alerted the community to look…

Superconductivity · Physics 2018-04-03 Ganapathy Baskaran

Magic-angle twisted bilayer graphene (MATBG) hosts a number of correlated states of matter that can be tuned by electrostatic doping. Superconductivity has drawn considerable attention and the mechanism behind it is a topic of active…

We present a theory of superconductivity in twisted bilayer graphene in which attraction is generated between electrons on the same honeycomb sublattice when the system is close to a sublattice polarization instability. The resulting Cooper…

Mesoscale and Nanoscale Physics · Physics 2022-10-26 Chunli Huang , Nemin Wei , Wei Qin , Allan MacDonald

We present a systematic theory of acoustic-phonon-mediated superconductivity, which incorporates Coulomb repulsion, explaining the recent experiment in Bernal bilayer graphene under a large displacement field. The acoustic-phonon mechanism…

Superconductivity · Physics 2022-03-18 Yang-Zhi Chou , Fengcheng Wu , Jay D. Sau , Sankar Das Sarma

For the unconventional superconducting phases in moire materials, a critical question is the role played by electronic interactions in the formation of Cooper pairs. In twisted bilayer graphene (tBLG), the strength of electronic…

The discovery of superconducting and insulating states in magic angle twisted bilayer graphene (MATBG) has ignited considerable interest in understanding the nature of electronic interactions in this chemically pristine material system. The…

Mesoscale and Nanoscale Physics · Physics 2019-08-02 Yonglong Xie , Biao Lian , Berthold Jäck , Xiaomeng Liu , Cheng-Li Chiu , Kenji Watanabe , Takashi Taniguchi , B. Andrei Bernevig , Ali Yazdani

Magic-angle twisted trilayer graphene (MATTG) has emerged as a novel moir\'e material that exhibits both strong electronic correlations and unconventional superconductivity. However, spectroscopic studies of its electronic properties are…

We consider the superconducting and Mott-insulating states for the twisted bilayer graphene, modeled as two narrow-band system of electrons with appreciable intraatomic Coulomb interactions. The interaction induces kinetic exchange which…

Superconductivity · Physics 2018-08-29 Maciej Fidrysiak , Michał Zegrodnik , Józef Spałek

Magic-angle twisted bilayer graphene (TBG), with rotational misalignment close to 1.1$^\circ$, features isolated flat electronic bands that host a rich phase diagram of correlated insulating, superconducting, ferromagnetic, and topological…

Twisted bilayer graphene (TBG) develops large moir\'e patterns at small twist angles with flat energy bands hosting domes of superconductivity. The large system size and intricate band structure have however hampered investigations into the…

Superconductivity · Physics 2022-07-19 Tomas Löthman , Johann Schmidt , Fariborz Parhizgar , Annica M. Black-Schaffer

The velocities of the quasiparticles that form Cooper pairs in a superconductor are revealed by the upper critical magnetic field. Here we use this property to assess superconductivity in magic-angle twisted bilayer graphene (MATBG), which…

Superconductivity · Physics 2021-02-23 Wei Qin , Bo Zou , Allan H. MacDonald