相关论文: Twisted Bilayer Graphene: A Phonon Driven Supercon…
In a groundbreaking experimental advance it was recently shown that by stacking two sheets of graphene atop of each other at a twist angle close to one of the so called "magic angles", an effective two-dimensional correlated system emerges.…
Identifying the microscopic mechanism for superconductivity in magic-angle twisted bilayer graphene (MATBG) is an outstanding open problem. While MATBG exhibits a rich phase-diagram, driven partly by the strong interactions relative to the…
Twisted bilayer graphene with a twist angle of around 1.1{\deg} features a pair of isolated flat electronic bands and forms a strongly correlated electronic platform. Here, we use scanning tunneling microscopy to probe local properties of…
Twisted bilayer graphene (tBLG) devices with ion gel gate dielectrics are studied using Raman spectroscopy in the twist angle regime where a resonantly enhanced G band can be observed. We observe prominent splitting and intensity quenching…
We present a computational study of the phonon linewidths in twisted bilayer graphene arising from electron-phonon interactions and anharmonic effects. The electronic structure is calculated using distance-dependent transfer integrals based…
In the magic-angle twisted bilayer graphene (MA-TBG), strong electron-electron (e-e) correlations caused by the band-flattening lead to many exotic quantum phases such as superconductivity, correlated insulator, ferromagnetism, and quantum…
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…
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 recently demonstrated unconventional superconductivity in twisted bilayer graphene (tBLG) opens the possibility for interesting applications of two-dimensional layers that involve correlated electron states. Here we explore the…
Using terahertz time-domain spectroscopy, the real part of optical conductivity [$\sigma_{1}(\omega)$] of twisted bilayer graphene was obtained at different temperatures (10 -- 300 K) in the frequency range 0.3 -- 3 THz. On top of a…
Thanks to the recent discovery on the magic-angle bilayer graphene, twistronics is quickly becom11 ing a burgeoning field in condensed matter physics. This letter expands the realm of twistronics to acoustics by introducing twisted bilayer…
In the presence of a large perpendicular electric field, Bernal-stacked bilayer graphene (BLG) features several broken-symmetry metallic phases as well as magnetic-field-induced superconductivity. The superconducting state is quite fragile,…
The discovery of different phases as a result of correlations, especially in low-dimensional materials, has been always an exciting and fundamental subject of research. Recent experiments on twisted bilayer graphene have revealed reentrant…
Magic-angle twisted bilayer graphene (MATBG) is notable as a highly tunable platform for investigating strongly correlated phenomena such as high-$T_c$ superconductivity and quantum spin liquids, due to easy control of doping level through…
Twisted bilayer graphene provides a new two-dimensional platform for studying electron interaction phenomena and flat band properties such as correlated insulator transition, superconductivity and ferromagnetism at certain magic angles.…
The microscopic pairing mechanism for superconductivity in magic-angle twisted bilayer graphene remains an open question. Recent experimental studies seem to rule out a purely electronic mechanism due to the insensitivity of the critical…
Twisted bilayer graphene (tBLG) is two graphene layers placed on top of each other with a twist angle, making it has tunable thermal properties. In this paper, we report an analysis of thermal conductivity ($\kappa$), phonon density of…
In this article, we review the recent discoveries of exotic phenomena in graphene, especially superconductivity. It has been theoretically suggested for more than one decade that superconductivity may emerge in doped graphene-based…
We propose a theory for how the weak phonon-mediated interaction ($J_{\rm A}\!=\!1\!\sim\!4$meV) wins over the prohibitive Coulomb repulsion ($U\!=\!30\!\sim\!60$meV) and leads to a superconductor in magic-angle twisted bilayer graphene…
We have studied the phonon specific heat in single-layer, bilayer and twisted bilayer graphene. The calculations were performed using the Born-von Karman model of lattice dynamics for intralayer atomic interactions and spherically symmetric…