Related papers: Optical sum rule in metals with a strong interacti…
The effects of random distribution of magnetic impurities with concentration $x$ in a semiconductor alloy multilayer at a paramagnetic temperature are investigated by means of coherent potential approximation and tight-binding model. The…
We study the dependence of the superconducting gaps on both the disorder and the temperature within the two-band model for iron-based materials. In the clean limit, the system is in the $s_\pm$ state with the sign-changing gaps. Scattering…
We calculate the radio-frequency spectrum of a trapped cloud of cold bosonic atoms in an optical lattice. Using random phase and local density approximations we produce both trap averaged and spatially resolved spectra, identifying simple…
Direct observation of temperature dependence of individual bands of semiconductors for a wide temperature region is not straightforward, in particular. However, this fundamental property is a prerequisite in understanding the…
We determined the complex dielectric functions of $\varepsilon$-Ga$_2$O$_3$ using optical transmittance and reflectance spectroscopies at temperatures from 10 K to room temperature. The measured dielectric-function spectra reveal distinct…
In the field of thermoelectric materials and devices, improving energy conversion efficiency remains a long-standing challenge. As a promising approach to address this issue, utilizing energy-dependent electron-scattering beyond the…
We investigate the thermodynamics of model systems exhibiting two-scale fractal spectra. In particular, we present both analytical and numerical studies on the temperature dependence of the vibrational and electronic specific heats. For…
The symmetry of the superconducting order parameter, or simply the ``gap'', provides certain constraints on the actual mechanism that gives rise to pairing and ultimately to superconductivity. In this work we show how superconducting phases…
Ultrafast laser measurements probe the non-equilibrium dynamics of excited electrons in metals with increasing temporal resolution. Electronic structure calculations can provide a detailed microscopic understanding of hot electron dynamics,…
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 sigma1(omega) of this…
Through the study of the power spectra of a monochromatic light beam reflected by metallic mirrors, fluctuations in their reflectance is observed. The power spectra were obtained down to a factor $10^{-6}$ below the Standard Quantum Limit,…
In the present work, we show the importance of temperature dependent energy band gap, E$_{g}$(T), in understanding the high temperature thermoelectric (TE) properties of material by considering LaCoO$_{3}$ (LCO) and ZnV$_{2}$O$_{4}$ (ZVO)…
We compute the transient dynamics of phonons in contact with high energy "hot" charge carriers in 12 polar and non-polar semiconductors, using a first-principles Boltzmann transport framework. For most materials, we find that the decay in…
Although the BCS theory of superconductivity is a well established theory, we have shown that the phenomenology predicted by this model is much richer than previously believed. By releasing the constraint that the attraction band is…
We study a four-band model for the iron oxypnictides, in which the superconducting properties are assumed to be determined by the interband coupling between hole-like and electron-like Fermi sheets. We show that reasonable parameters can…
We study pairing correlations in ultrasmall superconductor in the nanoscopic limit by means of a toy model where electrons are confined in a single, multiply degenerate energy level. We solve the model exactly to investigate the temperature…
Results for pseudogaps are obtained from a band model, where the stability of the gap depends on the amplitudes of vibrational displacements, or magnetic moments, and their coupling to electrons. A one-particle gap is favored by normal…
Using molecular dynamics simulations in a planar graphene sheet, we investigate the temperature dependence of its mechanical behavior under uniaxial tensile stress applied either along the armchair or the zigzag direction. Stress-strain…
By taking advantage of a stability criterion established recently, the critical temperature $T_c$ is reckoned with help of the microscopic parameters, characterising the normal and superconducting electrons, namely the independent-electron…
Sum rules constraining the R-current spectral densities are derived holographically for the case of D3-branes, M2-branes and M5-branes all at finite chemical potentials. In each of the cases the sum rule relates a certain integral of the…