The temperature dependence of the electronic structure of CeBi arising from two types of antiferromagnetic transitions based on optical conductivity (σ(ω)) was observed. The σ(ω) spectrum continuously and discontinuously changes at 25 and 11 K, respectively. Between these temperatures, two peaks in the spectrum rapidly shift to the opposite energy sides as the temperature changes. Through a com...

We present novel infrared optical conductivity data on the three layer high Tc superconductor Bi2Sr2Ca2Cu3O10 at optimal doping. We extend the analysis of an earlier publication, providing a universal scaling function σ(ω, T ) = T−1g(ω/T ) for the optical conductivity. In the present manuscript we obtain a good scaling collapse of the experimental curves on the g(ω/T ) over a wide range of valu...

A fundamental understanding of phonon transport in stanene is crucial to predict the thermal performance in potential stanene-based devices. By combining first-principle calculation and phonon Boltzmann transport equation, we obtain the lattice thermal conductivity of stanene. A much lower thermal conductivity (11.6 W/mK) is observed in stanene, which indicates higher thermoelectric efficiency ...

Various band structure engineering methods have been studied to improve the performance of graphitic transparent conductors; however, none has demonstrated an increase of optical transmittance in the visible range. Here we measure in situ optical transmittance spectra and electrical transport properties of ultrathin graphite (3-60 graphene layers) simultaneously during electrochemical lithiatio...

We report the lattice thermal conductivity (κ) of cubic boron nitride (c-BN) under pressure calculated using density functional theory. Pressure was used to manipulate the c-BN phonon dispersion and study its effect on thermal conductivity. These results were compared to c-BN's mass-equivalent, nonpolar counterpart, diamond, in order to isolate the effect of polar bonds on thermal conductivity....

The optical conductivity of CuO2 (copper-oxygen) planes in p and n–type cuprates thin films at various doping levels is deduced from highly accurate reflectivity data. The temperature dependence of the real part σ1(ω) of this optical conductivity and the corresponding spectral weight allow to track the opening of a partial gap in the normal state of n-type Pr2−xCexCuO4 (PCCO), but not of p–type...

S. Saberi-Pouya, 2 T. Vazifehshenas, ∗ T. Salavati-fard, M. Farmanbar, and F. M. Peeters Department of Physics, Shahid Beheshti University, G. C., Evin, Tehran 1983969411, Iran Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA Faculty of Science and Technology and MESA...

La8−xSrxCu8O20 is a non-superconducting cuprate, which exhibits a doubling of the elementary cell along the c axis. Its optical conductivity σ(ω) has been first measured here, down to 20 K, in two single crystals with x = 1.56 and x = 2.24. Along c σ(ω) shows, in both samples, bands due to strongly bound charges, thus confirming that the cell doubling is due to charge ordering. In the ab plane,...

We describe a phantom which enables EEG and near-infrared optical tomography to be performed simultaneously over the same volume. The phantom provides a surface electrical contact impedance comparable to that of the human scalp, whilst also possessing an optical scattering coefficient and electrical conductivity equivalent to that of brain tissue. The construction of the phantom is described, a...

Understanding the lattice dynamics and low thermal conductivities of IV-VI, V2-VI3 and V materials is critical to the development of better thermoelectric and phase-change materials. Here we provide a link between chemical bonding and low thermal conductivity. Our first-principles calculations reveal that long-ranged interaction along the 〈100〉 direction of the rocksalt structure exist in lead ...