Related papers: Multiple-source optical spectral weight transfer i…
The optical conductivity $\sigma_{1}(\omega)$ of Eu$_{1-x}$Ca$_{x}$B$_{6}$ has been obtained from reflectivity and ellipsometry measurements for series of compositions, $0\leq x\leq 1$. The interband part of $\sigma_{1}(\omega) $ shifts…
We report a detailed study of UGe$_{2}$ single crystals using infrared reflectivity and spectroscopic ellipsometry. The optical conductivity suggests the presence of a low frequency interband transition and a narrow free-carrier response…
The temperature dependence of the in-plane optical conductivity has been determined for Fe$_{1.03}$Te above and below the magnetic and structural transition at $T_N\simeq 68$ K. The electron and hole pockets are treated as two separate…
We present results of our broadband ellipsometry measurements of the optical response of ferromagnetic La$_{0.7}$Sr$_{0.3}$CoO$_3$. Our data show that the ferromagnetic transition is accompanied by a transfer of optical spectral weight from…
The optical conductivity of MgB$_2$ has been determined on a dense polycrystalline sample in the spectral range 6 meV - 4.6 eV using a combination of ellipsometric and normal incidence reflectivity measurements. $\sigma_{1}(\omega)$…
Magnetic field ($H$)-dependent optical conductivity spectra $\sigma (\omega) $ and dielectric constant spectra $\epsilon (\omega)$ of a layered antiferromagnet ($A$-type) Pr$_{1/2}$Sr$_{1/2}$MnO$_3$ were presented. At 0.0 T in 4.2 K, the…
Substituting $Eu$ by $Ca$ in ferromagnetic $EuB_6$ leads to a percolation limited magnetic ordering. We present and discuss magneto-optical data of the $Eu_{1-x}Ca_{x}B_6$ series, based on measurements of the reflectivity $R(\omega)$ from…
The temperature dependent redistribution of the spectral weight of the $CuO_2$ plane derived conduction band of the $YBa_2Cu_3O_{6.9}$ high temperature superconductor (T_c = 92.7 K) was studied with wide-band (from 0.01 to 5.6 eV)…
We show that, in antiferromagnetic superconductors, the optical spectral weight transferred to low frequencies below the superconducting transition temperature originates from energies that can be much larger than twice the superconducting…
To understand the halfmetallic ferromagnet EuB6 we use the Kondo lattice model for valence and conduction band. By means of a recently developed many-body theory we calculate the electronic properties in the ferromagnetic regime up to the…
The temperature dependence of the electronic structure of CeBi arising from two types of antiferromagnetic transitions based on optical conductivity ($\sigma(\omega)$) was observed. The $\sigma(\omega)$ spectrum continuously and…
We investigated optical absorption coefficient spectra of an epitaxial VO2 film in wide photon energy (0.5 - 5.0 eV) and temperature (100 - 380 K) regions. In its insulating phase, we observed two d-d transition peaks around 1.3 eV and 2.7…
We present a magnetotransport study of the low--carrier density ferromagnet EuB_6. This semimetallic compound, which undergoes two ferromagnetic transitions at T_l = 15.3 K and T_c = 12.5 K, exhibits close to T_l a colossal…
A room-temperature infrared spectroscopy study of elemental tellurium at pressures up to 8.44 GPa in the energy range 0.015-2 eV is reported. Optical signatures of the high-pressure polymorphs are investigated and compared to the results of…
We performed femtosecond reflection spectroscopy on a series of perovskite-type cobalt oxide $R$BaCo$_2$O$_{6-\delta}$ ($R$=Sm, Gd, and Tb) crystals, in which the electronic transfer was controlled by $R$. The transient reflectivity and the…
The magnetic-field dependence of optical reflectivity [$R(\omega)$] and optical conductivity [$\sigma(\omega)$] spectra of the ideal type-I Weyl semimetal TaAs has been investigated at the temperature of 10 K in the terahertz (THz) and…
The optical spectrum of the cubic helimagnetic metal FeGe has been investigated in the frequency range from 0.01 - 3.1 eV for different temperatures from 30 K to 296 K. The optical conductivity shows the evolution of a low energy (0.22 eV)…
We measured the reflectivity of the multifold semimetal RhSi in a frequency range from 80 to 20000 cm$^{-1}$ (10 meV - 2.5 eV) at temperatures down to 10 K. The optical conductivity, calculated from the reflectivity, is dominated by the…
We report optical (6 meV - 4 eV) properties of a boride superconductor ZrB$_{12}$ ($T_c$ = 6 K) in the normal state from 20 to 300 K measured on high-quality single crystals by a combination of reflectivity and ellipsometry. The Drude…
We present a detailed analysis of the superconductivity-induced redistribution of optical spectral weight in Bi2Sr2CaCu2O8 near optimal doping. It confirms the previous conclusion by Molegraaf et al. (Science 66, 2239 (2002)), that the…