Related papers: Origin of Universal Optical Conductivity and Optic…
We generalize the Bergman-Milton spectral representation, originally derived for a two-component composite, to extract the spectral density function for the effective dielectric constant of a graded composite. This work has been motivated…
We analyze the origin of superconductivity in a ferromagnetically ordered state of multi-layer graphene systems placed in proximity to WSe$_2$. We model these materials by a two-valley system of interacting fermions with small pockets and…
We measured the optical reflectivity of [001]-oriented $n$-doped Cd$_{3}$As$_{2}$ in a broad frequency range (50 - 22000 cm$^{-1}$) for temperatures from 10 to 300 K. The optical conductivity, $\sigma(\omega) = \sigma_{1}(\omega) + {\rm…
We study optical manifestations of multigap band topology in multiband superconductors with a nontrivial topological Euler class. We introduce a set of lattice models for non-Abelian superconductors with the Euler invariant signified by a…
We consider the real part of the conductivity, \sigma_1(\omega), arising from classical phase fluctuations in a model for high-T_c superconductors. We show that the frequency integral of that conductivity, \int_0^\infty \sigma_1 d\omega, is…
The optical conductivity of graphene nanoribbons is analytical and exactly derived. It is shown that the absence of translation invariance along the transverse direction allows considerable intra-band absorption in a narrow frequency window…
We report measurements of magnetoresistance in single-layer graphene as a function of gate voltage (carrier density) at 250 mK. By examining signatures of weak localization (WL) and universal conductance fluctuations (UCF), we find a…
We study the Coulomb drag transresistivity between graphene layers employing the finite temperature density response function. We analyze the Coulomb coupling between the two layers and show that a universal scaling behavior, independent of…
Multilayer graphene materials have recently emerged as a fascinating versatile platform for correlated electron phenomena, hosting superconductivity, fractional quantum Hall states, and correlated insulating phases. A particularly striking…
In quantum systems, signatures of multifractality are rare. They have been found only in the multiscaling of eigenfunctions at critical points. Here we demonstrate multifractality in the magnetic-field-induced universal conductance…
The criterion for the maximum incoherent conductivity $\sigma_{c,max}$ in the anisotropic system is shown to be $\sigma_{c,max} \sigma_{ab}=C (e^2/h)^2 n_{2D}$, where $n_{2D}$ is the two-dimensional electron density, and $C$ is a numerical…
Understanding the origin of electron incoherence is believed to be the first step toward the resolution of the mysteries of the high-T$_{c}$ cuprate superconductors. Such electron incoherence manifests itself most evidently in the non-Drude…
We study the optical response of bilayer graphene with a kink potential composed of a domain wall separating two AB regions with opposite interlayer bias. The band structure and the local optical conductivity in real space are investigated…
Superconductivity (SC) is a ubiquitous feature of graphite allotropes, having been observed in Bernal bilayers[1], rhombohedral trilayers[2], and a wide variety of angle-misaligned multilayers[3-6]. Despite significant differences in the…
Scattering dynamics influence the graphenes transport properties and inhibits the charge carrier deterministic behaviour. The intra or inter-band scattering mechanisms are vital for graphenes optical conductivity response under specific…
We have examined the interfacial thermal conductance {\sigma}int of single and multi-layer graphene samples prepared on fused SiO2 substrates by mechanical exfoliation of graphite. By using an ultrafast optical pump pulse and monitoring the…
We theoretically consider the effect of plasmon collective modes on the frequency-dependent conductivity of graphene in the presence of the random static potential of charged impurities. We develop an equation of motion approach suitable…
The observed 97.7% optical transparency of graphene has been linked to the value 1/137 of the fine structure constant, by using results for noninteracting Dirac fermions. The agreement in three significant figures requires an explanation…
We propose an explanation for the appearance of superconductivity at the interfaces of graphite with Bernal stacking order. A network of line defects with flat bands appears at the interfaces between two slightly twisted graphite…
While the Dirac band structure of graphene has established it as a leading platform for ultrafast optoelectronics, its non-perturbative nonlinear response under intense excitation remains poorly understood. Here, we report ultrafast…