The low-temperature asymptotic expressions for the Casimir interaction between two real metals described by Leontovich surface impedance are obtained in the framework of thermal quantum field theory. It is shown that the Casimir entropy computed using the impedance of infrared optics vanishes in the limit of zero temperature. By contrast, the Casimir entropy computed using the impedance of the ...

The numerical study of electromagnetic wave propagation in nanophotonic devices requires among others the integration of various types of dispersion models, such as the Drude one, in numerical methodologies. Appropriate approaches have been extensively developed in the context of the Finite Differences Time-Domain (FDTD) method, such as in [1] for example. For the discontinuous Galerkin time-do...

We consider spin accumulation at a ferromagnet–normal metal interface in the presence of magnetic scattering in the normal metal. In the classical regime, we discuss the inverse Drude scaling of the conductance as a function of the interface transparencies. We present a treatment based on an exact solution of the Boltzmann equation. In the quantum regime, we solve a single impurity “spin-flip F...

The temperature dependence of the in-plane optical conductivity has been determined for Fe1.03Te above and below the magnetic and structural transition at TN 68 K. The electron and hole pockets are treated as two separate electronic subsystems: a strong, broad Drude response that is largely temperature independent, and a much weaker, narrow Drude response with a strong temperature dependence. S...

We demonstrate a semiconductor based broadband near-field superlens in the mid-infrared regime. Here, the Drude response of a highly doped n-GaAs layer induces a resonant enhancement of evanescent waves accompanied by a significantly improved spatial resolution at radiation wavelengths around λ = 20 μm, adjustable by changing the doping concentration. In our experiments, gold stripes below the ...

We investigate the transient photoconductivity of graphene at various gate-tuned carrier densities by optical-pump terahertz-probe spectroscopy. We demonstrate that graphene exhibits semiconducting positive photoconductivity near zero carrier density, which crosses over to metallic negative photoconductivity at high carrier density. These observations can be accounted for by the interplay betwe...

An old classical one-particle helix model for optical activity, first proposed by Drude, is reconsidered here. The quantum Drude model is very instructive because the optical activity can be calculated analytically without further approximations apart from the Rosenfeld long wavelength approximation. While it was generally believed that this model, when treated correctly, is optically inactive,...

We measure the real and imaginary conductivity s(k50,v) of a high-mobility two-dimensional electron gas ~2DEG! system at frequencies below and above the momentum scattering rate. The imaginary part of the 2DEG impedance is observed to be inductive, consistent with the Drude model. Using this kinetic inductance, we construct a transmission line by capacitively coupling the 2DEG to an Al Schottky...

Negative entropy has been known in Casimir systems for some time. For example, it can occur between parallel metallic plates modeled by a realistic Drude permittivity. Less well known is that negative entropy can occur purely geometrically, say between a perfectly conducting sphere and a conducting plate. The latter effect is most pronounced in the dipole approximation, which is reliable when t...

A remarkable feature of vanadium dioxide is that it can be synthesized in a number of polymorphs. The conductivity mechanism in the metastable layered polymorph VO2(B) thin films has been investigated by terahertz time-domain spectroscopy (THz-TDS). In VO2(B), a critical temperature of 240 K marks the appearance of a non-zero Drude term in the observed complex conductivity, indicating the evolu...