相关论文: Hybridization and Slow Coherence Crossover in the …
Infrared optical conductivity [$\sigma(\omega)$] of the intermediate valence compound YbAl$_3$ has been measured at temperatures 8 K $\leq T \leq$ 690 K to study its microscopic electronic structures. Despite the highly metallic characters…
Mesoscopic transport measurements are underexplored as probes of quasiparticles and their properties in correlated metals. The mixed valence compound YbAl$_3$ exhibits a single-ion Kondo temperature of 670 K, while thermodynamic and…
The intermediate valence compound YbAl3 exhibits a broad magnetic excitation with characteristic energy E1 ~ 50meV, of order of the Kondo energy (TK ~ 600-700K). In the low temperature (T < Tcoh ~ 40K) Fermi liquid state, however, a new…
We report the electronic structure of a prototypical valence fluctuation system, YbAl2, using angle-resolved photoemission spectroscopy. The observed band dispersions and Fermi surfaces are well described in terms of band structure…
We present results from point-contact spectroscopy of the antiferromagnetic heavy-fermion superconductor UPd$_2$Al$_3$: conductance spectra are taken from single crystals with two major surface orientations as a function of temperature and…
The optical properties of the heavy-fermion compound UPd$_2$Al$_3$ have been measured in the frequency range from 0.04 meV to 5 meV (0.3 to 40 cm$^{-1}$) at temperatures $2 {\rm K}<T< 300$ K. Below the coherence temperature $T^*\approx 50$…
Experimental results for the susceptibility, specific heat, 4f occupation number, Hall effect and magnetoresistance for single crystals of YbAl$_{3}$ show that, in addition to the Kondo energy scale $k_{B}T_{K}$ $% \sim $ 670K, there is a…
YbInCu$_4$ undergoes a first order structural phase transition near $T_v$=40 K associated with an abrupt change of Yb valence state. We perform ultrafast pump-probe measurement on YbInCu$_4$ and find that the expected heavy fermion…
We report the ultrafast optical pump-probe spectroscopy measurements on the recently discovered quantum critical ferromagnet CeRh$_6$Ge$_4$. Our experimental results reveal the two-stage development of the hybridization between localized…
Based on the recently proposed band model, the electronic specific heat of moderately heavy electron compound YbAl$_3$ are investigated. The band term of the Hamiltonian consists of three parts; conduction electrons described by the nearly…
\beta-YbAlB_4 is the unique heavy fermion superconductor that exhibits unconventional quantum criticality without tuning in a strongly intermediate valence state. Despite the large coherence temperature, set by the peak of the longitudinal…
In Kondo lattice systems with mixed valence, such as YbAl3, interactions between localized electrons in a partially filled f shell and delocalized conduction electrons can lead to fluctuations between two different valence configurations…
Femtosecond time-resolved optical spectroscopy was used to systematically study photoexcited carrier relaxation dynamics in the intermediate-valence heavy fermion system Yb1-xLuxAl3 (0 < x < 1). Given the demonstrated sensitivity of this…
We present THz measurements of thin films of mixed-valent YbAl$_3$ and its structural analogue LuAl$_3$. Combined with traditional Fourier transform infrared (FTIR) spectroscopy, the extended Drude formalism is utilized to study the…
We report a detailed study of soft-point-contact spectroscopy of the superconducting topological nodal-line semimetal Sn$_{0.15}$NbSe$_{1.75}$ with the superconducting transition temperature $T_{c}=9.5$ K. In the normal state, we observe…
We show for the intermediate valence compound YbAl$_{3}$ that the high field (40 $\lesssim B \lesssim$ 60T) effective masses measured by the de Haas-van Alphen experiment for field along the $<111>$ direction are smaller by approximately a…
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,…
We present magnetization, specific heat, and 27Al NMR investigations on YbFe2Al10 over a wide range in temperature and magnetic field. The magnetic susceptibility at low temperatures is strongly enhanced at weak magnetic fields, accompanied…
We have measured the superconducting penetration depth~$\Lambda(T)$ in the heavy-fermion/intermediate-valent superconducting alloy series~Ce$_{1-x}$Yb$_x$CoIn$_5$ using transverse-field muon spin relaxation, to study the effect of…
$\alpha$-YbAlB$_4$ is the locally isostructural polymorph of $\beta$-YbAlB$_4$, the first example of an Yb-based heavy fermion superconductor which exhibits pronounced non-Fermi-liquid behavior above $T_{\rm c}$. Interestingly, both…