Phase analysis of quantum oscillations in graphite

The quantum de Haas van Alphen (dHvA) and Shubnikov de Haas (SdH) oscillations measured in graphite were decomposed by pass-band filtering onto contributions from three different groups of carriers. We develop the two-dimensional phase analysis method which allows to identify these carriers as (i) minority holes having two-dimensional (2D) parabolic massive spectrum, (ii) majority electrons, also massive but with intermediate 2D-3D spectrum, and (iii) majority holes with 2D Dirac-like spectrum which seems to be responsible for the unusual strongly-correlated electronic phenomena in graphite.Comment: latest version as was published in PR

Comment on "Consistent Interpretation of the Low-Temperature Magnetotransport in Graphite Using the Slonczewski-Weiss-McClure 3D Band-Structure Calculations" (arXiv:0902.1925)

In 2004 we have shown that substantial part of conductivity in graphite is provided by holes with massless linear spectrum - Dirac Fermions that coexist with massive normal carriers - electrons. In a recent Letter [Phys. Rev. Lett. 102, 166403 (2009), arXiv:0902.1925] Schneider et al. revised our conclusion pointed that both types of carriers are massive. Since both groups use the same method of phase determination of Shubnikov de Haas oscillation we comment here that the controversy originates from the improper treatment of experimental results in Schneider2009 et al

Sound modes in composite incommensurate crystals

We propose a simple phenomenological model describing composite crystals, constructed from two parallel sets of periodic inter-penetrating chains. In the harmonic approximation and neglecting thermal fluctuations we find the eigenmodes of the system. It is shown that at high frequencies there are two longitudinal sound modes with standard attenuation, while in the low frequency region there is one propagating sound mode and an over-damped phase mode. The crossover between these two regions is analyzed numerically and the dynamical structure factor is calculated. It is shown that the qualitative features of the experimentally observed spectra can be consistently described by our model.Comment: 12 pages, 2 eps figures, Revtex, accepted to European Physics Journal B, (2002

Optical anapoles in nanophotonics and meta-optics

Interference of electromagnetic modes supported by subwavelength photonic structures is one of the key concepts that underpins the subwavelength control of light in meta-optics. It drives the whole realm of all-dielectric Mie-resonant nanophotonics with many applications for low-loss nanoscale optical antennas, metasurfaces, and metadevices. Specifically, interference of the electric and toroidal dipole moments results in a very peculiar, low-radiating optical state associated with the concept of optical anapole. Here, we uncover the physics of multimode interferences and multipolar interplay in nanostructures with an intriguing example of the optical anapole. We review the recently emerged field of anapole electrodynamics explicating its relevance to multipolar nanophotonics, including direct experimental observations, manifestations in nonlinear optics, and rapidly expanding applications in nanoantennas, active photonics, and metamaterials.Comment: 14 pages, 6 figure