Related papers: Dynamic Kohn anomaly in twisted bilayer graphene
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…
We calculate the screening function in bilayer graphene (BLG) both in the intrinsic (undoped) and the extrinsic (doped) regime within random phase approximation, comparing our results with the corresponding single layer graphene (SLG) and…
Two new Raman modes below 100 cm^-1 are observed in twisted bilayer graphene grown by chemical vapor deposition. The two modes are observed in a small range of twisting angle at which the intensity of the G Raman peak is strongly enhanced,…
When two sheets of graphene stack in a twisted bilayer graphene (tBLG) configuration, the resulting constrained overlap between interplanar 2p orbitals produce angle-tunable electronic absorption resonances. Using a novel combination of…
It is a matter of current debate whether the gate-tunable superconductivity in twisted bilayer graphene is phonon-mediated or arises from electron-electron interactions. The recent observation of the strong coupling of electrons to…
In graphene, charged defects break the electron-hole symmetry and can even give rise to exotic collapse states when the defect charge exceeds a critical value which is proportional to the Fermi velocity. In this work, we investigate the…
We have surveyed the in-plane transport properties of the graphene twist bilayer using (i) a low-energy effective Hamiltonian for the underlying electronic structure, (ii) an isotropic elastic phonon model, and (iii) the linear Boltzmann…
We investigate imaging of moire structures in free-standing twisted bilayer graphene (TBG) carried out by transmission electron microscopy (TEM) in diffraction and in-line Gabor holography modes. Electron diffraction patterns of TBG…
Interactions with electronic excitations can soften and/or broaden phonons. They are greatly amplified at wavevectors Q+- that connect parallel (nested) sheets of the Fermi surface. In such a case, called a Kohn anomaly, the phonon…
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…
The rich physics of magic angle twisted bilayer graphene (TBG) results from the Coulomb interactions of electrons in flat bands of non-trivial topology. While the bands' dispersion is well characterized, accessing their topology remains an…
Evidence of flat-band magnetism and half-metallicity in compressed twisted bilayer graphene is provided with first-principles calculations. We show that dynamic band-structure engineering in twisted bilayer graphene is possible by…
The phonon spectra of twisted bilayer graphene (tBLG) are analyzed for a series of 692 twisting angle values in the $[0,30{\degree}]$ range. The evolution of the phonon bandstructure as a function of twist angle is examined using a band…
The tunability of the interlayer coupling by twisting one layer with respect to another layer of two-dimensional materials provides a unique way to manipulate the phonons and related properties. We refer to this engineering of phononic…
The polarizability of twisted bilayer graphene, due to the combined effect of electron-hole pairs, plasmons, and acoustic phonons is analyzed. The screened Coulomb interaction allows for the for- mation of Cooper pairs and superconductivity…
Magic angle twisted bilayer graphene has emerged as a powerful platform for studying strongly correlated electron physics, owing to its almost dispersionless low-energy bands and the ability to tune the band filling by electrostatic gating.…
Owing to the interaction between the layers, the twisted bilayer two-dimensional materials exhibit numerous unique optical and electronic properties different from the monolayer counterpart, and have attracted tremendous interests in…
We study the variations of electron-phonon coupling and their spectroscopic consequences in response to sliding of two layers in bilayer graphene using first-principles calculations and a model Hamiltonian. Our study shows that the long…
Spontaneous orbital magnetism observed in twisted bilayer graphene (tBG) on nearly aligned hexagonal boron nitride (BN) substrate builds on top of the electronic structure resulting from combined G/G and G/BN double moire interfaces. Here…
Graphene-based moir\'{e} systems have attracted considerable interest in recent years as they display a remarkable variety of correlated phenomena. Besides insulating and superconducting phases in the vicinity of integer fillings of the…