Related papers: The Kondo Dynamics of YbIn(1-x)AgxCu4
Theoretical work on Kondo systems predicts universality in the scaling of observable quantities with the Kondo temperature, T_K. Here we report infrared-frequency optical response measurements of the correlated system \ybinag. We observe…
Infrared, visible and near-UV reflectivity measurements are used to obtain conductivity as a function of temperature and frequency in YbInCu_4, which exhibits an isostructural phase-transition into a mixed-valent phase below T_v=42 K. In…
Infrared measurements are used to obtain conductivity as a function of temperature and frequency in YbInCu_4, which exhibits an isostructural transition to a mixed-valent state at T_v \simeq 42 K. In addition to a gradual loss of spectral…
[published in Phys. Rev. B 85, 035119 (2012)] The evolution of spin dynamics from the quantum critical system YbRh2Si2 to the stable trivalent Yb system YbCo2Si2 was investigated by Electron Spin Resonance (ESR) spectroscopy. While the…
We report the temperature dependence of the Yb valence in the geometrically frustrated compound $\mathrm{YbB_4}$ from 12 to 300 K using resonant X-ray emission spectroscopy at the Yb $L_{\alpha_1}$ transition. We find that the Yb valence,…
The doping and temperature dependence of the electronic Raman response in cuprate superconductors is studied within the framework of the kinetic energy driven superconducting mechanism for the t-J model. It is shown that the temperature…
Recently, it was reported by MacLaughlin et al. in Phys. Rev. B 93, 214421 (2016) that \alpha-YbAl_{0.986}Fe_{0.014}B_4 exhibits an anomalous temperature dependence in the relaxation rate 1/T_{1} of $\mu$SR, and stressed that such…
Detailed doping dependence of the electronic specific heat coefficient gamma is studied for La2-xSrxCuO4 (LSCO) single crystals in the slightly-doped regime. We find that gamma systematically increases with doping, and furthermore, even for…
We studied the doping and temperature (T) dependence of the infrared (IR) response of Ba(Fe1-xCox)2As2 single crystals. We show that a weak band around 1000 cm-1, that was previously interpreted in terms of interaction of the charge…
We measure the penetration depth of optimally doped and underdoped La2-xCexCuO4 in the millimeter frequency domain (4 - 7 cm-1) and for temperatures 2 K < T < 300 K. The penetration depth as function of temperature reveals significant…
Infrared spectroscopy has emerged as a premier experimental technique to probe enigmatic effects arising from strong correlations in solids. Here we report on recent advances in this area focusing on common patterns in correlated electron…
We have studied the photoexcited carrier relaxation dynamics in the Kondo insulator SmB6 and the heavy fermion metal YbAgCu4 as a function of temperature and excitation level. The dynamic response is found to be both strongly temperature…
The electronic properties of Cerium (Ce) and ytterbium (Yb) intermetallic compounds may display a more local or more itinerant character depending on the interplay of the exchange interactions among the $4f$ electrons and the Kondo coupling…
We report the first study of electrical resistivity, magnetization, and specific heat on YbCo$_2$. The measurements on a single-phased sample of YbCo$_2$ bring no evidence of magnetic ordering down to 0.3 K in a zero magnetic field. The…
Carrier dynamics in amorphous a-Si$_{1-x}$RE$_{x}$ (RE=Gd, Y) films has been studied in the doping regime close to the metal-insulator transition by means of infrared spectroscopy. Optical constants throughout the entire intra-gap region…
Theoretical ideas and experimental results concerning high temperature superconductors are reviewed. Special emphasis is given to calculations carried out with the help of computers applied to models of strongly correlated electrons…
Structural, magnetic, transport and thermal properties of YbCu5-xAux alloys with Au concentration between the limit of structural stability of AuBe5 type at x = 0.4 up to x = 0.7 are reported. The outstanding features of this system are: i)…
We have re-examined the temperature-doping (T-p) phase diagram of YBa2Cu3Oy (YBCO) to address several issues therein by using the temperature derivative of in-plane resistivity, d\{rho}ab/dT. For p less than about 0.15, a temperature Tf has…
Recently, above-room temperature superconductivity was reported in the Cu doped lead apatite Pb$_{10-x}$Cu$_x$(PO4)$_6$O, dubbed LK-99. By relaxing the structure with Cu substitution, we derive a four-band low-energy model with two 3/4…
The structural, electrical and magnetic properties of the superconducting ferromagnets, Gd1.4-xDyxCe0.6Sr2RuCu2O10 (x=0-0.6) are systematically investigated as a function of Dy doping and temperature. These compounds are characterised by…