Related papers: Slow crossover in YbXCu4 intermediate valence comp…
We investigate the Yb valence instabilities in the strongly correlated YbPd compound using resonant X-ray emission spectroscopy as a function of pressure across the charge-order (CO) transition. At a low temperature (T = 30 K) in the CO…
We report electrical resistivity, ac magnetic susceptibility and X-ray absorption spectroscopy measurements of intermediate valence YbNi$_{3}$Ga$_{9}$ under pressure and magnetic field. We have revealed a characteristic pressure-induced Yb…
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…
The single impurity Anderson model (SIAM) is studied within an enhanced non-crossing approximation (ENCA). This method is extended to the calculation of susceptibilities and thoroughly tested, also in order to prepare applications as a…
We report on single crystal growth and physical properties of the quantum critical Kondo-lattice system YbNi$_4$(P$_{1-x}$As$_{x}$)$_2$ with $0\leq x\leq 1$ which hosts a ferromagnetic quantum critical point at $x \approx 0.1$. We performed…
The thermodynamic and transport properties of intermetallic compounds with Ce, Eu, and Yb ions are discussed using the periodic Anderson model with an infinite correlation between $f$ electrons. The slave boson solution of the periodic…
Here we provide the first clear evidence of Fermi-liquid breakdown in an intermediate valence system. We employ high precision magnetization measurements of the valence fluctuating superconductor beta-YbAlB4 to probe the quantum critical…
Numerical renormalization-group results on entropy of the anisotropic two-channel Kondo model with the band-width cutoff ($D$) in the presence of a magnetic field ($h$) are obtained to determine crossover temperature from the non-Fermi…
We generalize Nozi\`eres' Fermi-liquid theory for the low-energy behavior of the Kondo model to that of the single-impurity Anderson model. In addition to the electrons' phase shift at the Fermi energy, the low-energy Fermi-liquid theory is…
Analyzing temperature dependent photoemission (PE) data of the ferromagnetic Kondo-lattice (KL) system YbNiSn in the light of the Periodic Anderson model (PAM) we show that the KL behavior is not limited to temperatures below a temperature…
We report the pressure dependences of the superconducting transition temperature (T_c) in several perovskite-type Fe-based superconductors through the resistivity measurements up to ~4 GPa. In Ca_4(Mg,Ti)_3Fe_2As_2O_y with the highest T_c…
An experimental technique of x-ray fluorescence holography for investigating valence-selective local structures was established by employing the incident x-ray energy at a characteristic one near an x-ray absorption edge, and it was adopted…
The physical properties of the very heavy fermion YbCu$_4$Ni were characterized through structural, magnetic, thermal and transport studies along nearly four decades of temperature ranging between 50 milikelvin and 300 K. At high…
The temperature (T) dependence of the muon and $^{63}$Cu nuclear spin-lattice relaxation rates $1/T_1$ in YbCu4.4Au0.6 is reported over nearly four decades. It is shown that for $T\to 0$ $1/T_1$ diverges following the behaviour predicted by…
Effects of the Co substitution have been observed on the structural, magnetic and magneto-transport properties of Fe2-xCoxMnSi alloy. Curie temperature (TC) and saturation magnetization (MS) of these alloys increased linearly with the Co…
Polycrystalline samples of Lu{1-x}Sc{x}MnSi (x= 0, 0.25, 0.50) are studied using powder x-ray diffraction (XRD), heat capacity Cp, magnetization M, magnetic susceptibility chi, and electrical resistivity rho measurements versus temperature…
In highly doped uncompensated p-type layers within the central part of GaAs/AlGaAs quantum wells at low temperatures we observed an activated behavior of the conductivity with low activation energies (1-3) meV which can not be ascribed to…
Alternating (AC) magnetic fields can induce not only an alternating magnetization in materials, but also an alternating temperature via the magnetocaloric effect. The latter effect is typically neglected when performing AC susceptibility…
The low-temperature behavior of the static magnetic susceptibility $\chi(T)$ of exchange-disordered antiferromagnetic spin chains is investigated. It is shown that for a relatively small and even number of spins in the chain, two exchange…
Similar to transitions in a range of correlated quantum materials, the valence transition exhibits a strong coupling to the crystal lattice, rendering it highly sensitive to stress tuning. In the present work, we determine the effect of…