Utilizing a complete Lorentz-covariant and local-gauge-invariant formulation, we discuss graphene response to arbitrary external electric field. The relation, which is called as Kramers-Krönig relation in the paper, between imaginary part and real part of ac conductivity is given. We point out there exists an ambiguity in the conductivity computing, attributed to the wick behavior at ultraviole...

An efficient electromagnetic shielding composite based on multiwalled carbon nanotubes (MWCNTs)-filled styrene acrylic emulsion-based polymer has been prepared in a water-based system. The MWCNTs were demonstrated to have an effect on the dielectric constants, which effectively enhance electromagnetic shielding efficiency (SE) of the composites. A low conductivity threshold of 0.23 wt% can be o...

A theoretical analysis is presented that allows in situ measurements of the physical properties of a composite electrode, namely, the electronic conductivity, the ionic conductivity, the exchange-current density, and the double-layer capacitance. Use is made of the current-voltage responses of the composite electrode to dc and ac polarizations under three different experimental configurations. ...

The frequency dependent ac conductivity and permittivity of porous lead zirconate titanate ceramic with the pore volume filled with water are shown to match the simulated electrical response of a large network of randomly positioned resistors and capacitors. Anomalous power law dispersions in conductivity and permittivity are shown to be an electrical response characteristic of the microstructu...

We describe a technique which enables angle-resolved mapping of the in-plane Fermi velocity svFd for a quasi-two-dimensional sQ2Dd conductor. The method is based on a magnetic resonance effect in the ac conductivity for in-plane magnetic fields, which has recently been successfully applied to a Q2D organic conductor. In this article, we consider the possibility of using this method to probe the...

We have used a millimeter-wave technique to probe the complex AC conductivity of (TMTSF)$104 in fields to 30 tesla. The fieldinduced-spin-density-wave (FISDW) transitions are clearly seen at low temperatures and low fields, as are the rapid oscillations at higher fields. In addition, we see evidence for a collective pinning mode of the FISDW at high fields.

The universality of the ac electrical transport in granular metals has been scarcely studied and the actual mechanisms involved in the scaling laws are not well understood. Previous works have reported on the scaling of capacitance and dielectric loss at different temperatures in Co-ZrO2 granular metals. However, the characteristic frequency used to scale the conductivity spectra has not been d...

I review some of the results on the Mott transition in one dimensional systems obtained in [1–3]. I discuss the phase diagram and critical properties of both Mott transitions at fixed filling and upon doping, as well as the dc and ac conductivity. Application of these results to organic conductors is discussed.

We study the ac-conductivity in linear response theory for the Anderson tight-binding model. We define the electrical acconductivity and calculate the linear-response current at zero temperature for arbitrary Fermi energy. In particular, the Fermi energy may lie in a spectral region where extended states are believed to exist.

Ehrenfest's theorem is used to derive the rate of change of kinetic energy induced by an external field. The expression for the power is valid for any electromagnetic field in arbitrary gauge. We discuss the applicable conditions for the Mott-Davis and Moseley-Lukes form of the Kubo-Greenwood formula (KGF) for the electrical conductivity which has been implemented in ab initio codes. We show th...