Related papers: Possible multi-orbital ground state in CeCu$_2$Si$…
We present thermal expansion and magnetostriction measurements on a CeCu2Si2 single crystal of A/S-type up to 17.9T magnetic field applied along the crystallographic a-direction (Delta L ll a ll H) and down to 0.015K temperature. We…
The $^{4}\Phi_{9/2}$ ground state of the Ni$_2^+$ diatomic molecular cation is determined experimentally from temperature and magnetic-field-dependent x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap, where an…
Locally noncentrosymmetric heavy-fermion compounds may produce long-sought correlated quantum phases, such as spin-triplet superconductivity with non-Abelian quasiparticles, but identifying the right candidate systems is challenging. Here,…
A quantum-mechanical model of Cu-O-Cu-O four-center four-electron part of the copper-oxide plane embedded in a superconducting crystal La$_{2-x}$Sr$% _{x}$CuO$_{4}$ (LSCO) is considered. It is shown that displacing the nearest-neighbor…
After a brief introduction to crystalline organic superconductors and metals, we shall describe two recently-observed exotic phases that occur only in high magnetic fields. The first involves measurements of the non-linear electrical…
We report the systematic synthesis, crystal structure, magnetization, and powder neutron diffraction of single crystalline and polycrystalline CaCo$_2$TeO$_6$ samples. CaCo$_2$TeO$_6$ crystallizes in an orthorhombic structure with $Pnma$…
We derive the coupling of a localized hexadecapolar mode to conduction electrons in tetragonal symmetry. The derivation can be easily adapted to arbitrary multipoles in arbitrary environment. We relate our model to the two-channel Kondo…
The Ce$^{3+}$ pseudospin-1/2 degrees of freedom in Ce$_2$Zr$_2$O$_7$ possess both dipolar and octupolar character which enables the possibility of novel quantum spin liquid ground states in this material. Here we report new muon spin…
We measured the resistivity and magnetic susceptibility to map out the phase diagram of single crystalline NaFe$_{1-x}$Co$_x$As. Replacement of Fe by Co suppresses both the structural and magnetic transition, while enhances the…
We report measurements of inelastic neutron scattering, magnetic susceptibility, magnetization, and the magnetic field dependence of the specific heat for the heavy Fermion compounds Ce$_3$In and Ce$_3$Sn. The neutron scattering results…
We measured the polarized optical conductivity of URu$_2$Si$_2$ from room temperature down to 5 K, covering the Kondo state, the coherent Kondo liquid regime, and the hidden-order phase. The normal state is characterized by an anisotropic…
The magnetic field and temperature dependencies of the magnetic moments of superconducting crystals of ${\rm V_{3}Si}$ have been studied. In a constant magnetic field and at temperatures somewhat below the superconducting transition…
We investigate the stability of the multipolar orderings in $f$-electron material CeCoSi based on a self-consistent mean-field calculation for the effective localized model. This material has two ordered phases in the temperature-pressure…
We present time-domain THz spectroscopy of thin films of the heavy-fermion superconductor CeCoIn$_5$. Below the $\approx$ 40 K Kondo coherence temperature, a narrow Drude-like peak forms, as the result of the $f$ orbital - conduction…
CeRh$_2$As$_2$ is an unconventional superconductor with multiple superconducting phases and $T_\mathrm{c} = 0.26$ K. When $H\parallel c$, it shows a field-induced transition at $\mu_0H^* = 4$ T from a low-field superconducting state SC1 to…
We have used temperature dependent x-ray absorption at the Ce-L3 edge to investigate the recently discovered Kondo compound Ce2Rh3Al9. The systematic changes of the spectral lineshape with decreasing temperature are analyzed and found to be…
We have measured both magnetoresistance and Hall effect in CeOs$_4$Sb$_{12}$ to clarify the large resistivity state ascribed to the Kondo insulating one and the origin of the phase transition near 0.9 K reported in the specific heat…
Contrary to conventional wisdom, our purified La2-2xSr1+2xMn2O7 crystals exhibit CE-type orbital and charge order as the low-temperature ground state for a hole doping level h = 0.5. For small deviations from h = 0.5, the high temperature…
We have investigated the ground state properties of polycrystalline CeCoAsO by means of magnetization, specific heat and solid state NMR. Susceptibility and specific-heat measurements suggest a ferromagnetic order at about,…
Thermal ($C_P$), magnetic ($M$ and $\chi_{ac}$) and transport ($\rho$) measurements on Ce$_{2}$Pd$_{2}$Sn are reported. High temperature properties are well described by the presence of two excited crystal field levels at $(65\pm 5)$K and…