Related papers: Terahertz conductivity of twisted bilayer graphene
We calculate the finite-frequency conductivity of bilayer graphene with a relative twist between the layers. The low frequency response at zero doping shows a flat conductivity with value twice that of the monolayer case and at higher…
This study theoretically investigates the contact conductance in twisted bilayer graphene (TBG), providing a theoretical explanation for recent experimental observations from scanning tunneling microscopy (STM) and conductive atomic force…
We numerically calculate the optical conductivity of twisted graphene bilayers within the continuum model. To obtain the imaginary part, we employ the regularized Kramers-Kronig relation allowing us to discuss arbitrary twist angles,…
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…
We report an experimental study of carrier density (n), displacement field (D) and twist angle ({\theta}) dependence of temperature (T)-linear resistivity in twisted double bilayer graphene (TDBG). For a large twist angle…
Superconductivity with transition temperature $T_c=1.7$ K has been reported in bilayer graphene [1,2]. The main factors, which may shed light on the mechanism of the formation of this superconductivity, are the following. Superconductivity…
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…
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…
We present a theoretical study of the local optical conductivity, plasmon spectra, and thermoelectric properties of twisted bilayer graphene (TBG) at different filling factors and twist angles $\theta$. Our calculations are based on the…
We performed phase-sensitive terahertz (0.12 - 1.2 THz) transmission measurements of Ga-enriched layers in silicon. Below the superconducting transition, T_{c} = 6.7 K, we find clear signatures of the formation of a superconducting…
A density-matrix formalism within the length gauge is developed for the purpose of calculating the nonlinear response of intrinsic bilayer graphene at terahertz frequencies. Employing a tight-binding model, we find that interplay between…
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…
Superconductivity has been previously observed in magic-angle twisted stacks of monolayer graphene but conspicuously not in twisted stacks of bilayer graphene, although both systems host topological flat bands and symmetry-broken states.…
Identifying the microscopic processes that limit conductivity is essential for understanding correlated and quantum-critical states in quantum materials. In twisted bilayer graphene (TBG) and other twist-controlled materials, the…
Using Terahertz Time-Domain Spectroscopy, we study the temperature-dependent complex optical conductivity of the topological insulator, Bi$_{1.5}$Sb$_{0.5}$Te$_{1.8}$Se$_{1.2}$ single-crystal from 5 K to 150 K in the terahertz regime (0.4…
Recent research on twisted bilayer graphene (TBG) uncovered that its twist-angle-dependent electronic structure leads to a host of unique properties, such as superconductivity, correlated insulating states, and magnetism. The flat bands…
Unconventional superconductivity in bilayer graphene has been reported for twist angles $\theta$ near the first magic angle and charged electrostatically with holes near half filling of the lower flat bands. A maximum superconducting…
Recent studies show that two low-energy Van Hove singularities (VHSs) seen as two pronounced peaks in the density of states (DOS) could be induced in twisted graphene bilayer. Here, we report angle dependent VHSs of slightly twisted…
In this paper, the electronic properties of 30{\deg} twisted double bilayer graphene, which loses the translational symmetry due to the incommensurate twist angle, are studied by means of the tight-binding approximation. We demonstrate the…
We performed electric and thermoelectric transport measurements of bilayer graphene in a magnetic field up to 15 Tesla. The transverse thermoelectric conductivity $\rm\alpha_{xy}$, determined from four transport coefficients, attains a peak…