Related papers: Optical-phonon resonances with saddle-point excito…
Using resonant 2-photon excitation of interlayer electrons in twisted bilayer graphene (tBLG), we resolve photoluminescence (PL) that tunes spectrally with stacking angle, {\theta}. This weak signal is 4- 5$\times$ larger than the…
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 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…
We report a systematic study of the optical conductivity of twisted bilayer graphene (tBLG) across a large energy range (1.2 eV to 5.6 eV) for various twist angles, combined with first-principles calculations. At previously unexplored high…
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…
Twisted bilayer graphene (tBLG) has recently emerged as a platform for hosting correlated phenomena, owing to the exceptionally flat band dispersion that results near interlayer twist angle $\theta\approx1.1^\circ$. At low temperature a…
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…
Bi-layer graphene with a twist angle \theta\ between the layers generates a superlattice structure known as Moir\'{e} pattern. This superlattice provides a \theta-dependent q wavevector that activates phonons in the interior of the…
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…
We theoretically study the band structure and optical conductivity of twisted bilayer graphene (TBG) near the magic angle considering the effects of lattice relaxation. We show that the optical conductivity spectrum is characterized by a…
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…
We investigate one- and two-photon absorption in twisted bilayer graphene (TBLG) by examining the effects of tuning the twist angle $ \theta $ and the excitation energy $ E_l $ on its absorption coefficients $ \alpha_{i=1,2}$. We find that…
Focusing on the twist angle for the minimal commensurate structure, we perform nonperturbative calculations of electron dynamics in the twisted bilayer graphene (TBG) under intense laser fields. We show that the TBG exhibits enriched…
Understanding and tuning correlated states is of great interest and significance to modern condensed matter physics. The recent discovery of unconventional superconductivity and Mott-like insulating states in magic-angle twisted bilayer…
Twisted bilayer graphene (tBLG) provides a fascinating platform for engineering flat bands and inducing correlated phenomena. By designing the stacking architecture of graphene layers, twisted multilayer graphene can exhibit different…
Twisted bilayer graphene (tBLG) has emerged as an exciting platform for novel condensed matter physics. However, electron-phonon ($e$-ph) interactions in tBLG and their effects on electronic transport are not completely understood. Here we…
We theoretically investigated phonon dispersion in AA-stacked, AB-stacked and twisted bilayer graphene with various rotation angles. The calculations were performed using the Born-von-Karman model for the intra-layer atomic interactions and…
The band structure of bilayer graphene is tunable by introducing a relative twist angle between the two layers, unlocking exotic phases, such as superconductor and Mott insulator, and providing a fertile ground for new physics. At…
We study the electron-phonon coupling in twisted bilayer graphene (TBG), which was recently experimentally observed to exhibit superconductivity around the magic twist angle $\theta\approx 1.05^\circ$. We show that phonon-mediated electron…
We calculate the contribution to the doping ($n$) and temperature ($T$) dependence of the electrical resistivity of twisted bilayer graphene (TBLG) due to scattering by acoustic phonons. Our calculation retains the full Bistritzer-MacDonald…