Related papers: Skutterudite Results Shed Light on Heavy Fermion P…
Neutron-scattering and specific-heat measurements of the heavy-fermion superconductor URu2Si2 under hydrostatic pressure and with Rh-doping [U(Ru{0.98}Rh{0.02})2Si2] show the existence of two magnetic phase transitions. At the second-order…
We address two important issues that arise in recent studies of iron-based superconductivity. (1) Why are the T_c of A_xFe_{2-y}Se_2 and the single unit cell FeSe on SrTiO$_3$ so high despite both only have electron pockets? (2) What (if…
Adding a second Kondo channel to heavy fermion materials reveals new exotic symmetry breaking phases associated with the development of Kondo coherence. In this paper, we review two such phases, the "hastatic order" associated with…
Nematic orders emerge nearly universally in iron-based superconductors, but elucidating their origins is challenging because of intimate couplings between orbital and magnetic fluctuations. The iron-based ladder material BaFe2S3, which…
Substitution of Re for Ru in the heavy fermion compound URu2Si2 suppresses the hidden order transition and gives rise to ferromagnetism at higher concentrations. The hidden order transition of URu(2-x)Re(x)Si2, tracked via specific heat and…
We report a comparative high-pressure study of two fluorite-type rare-earth oxides with increasing configurational entropy, (CePr)O$_{2-{\delta}}$ and (CePrLa)O$_{2-{\delta}}$. Synchrotron-based powder X-ray diffraction and Raman…
We review the recent developments in the field of cuprate superconductors with the special focus on the recently observed charge order in the underdoped compounds. We introduce new theoretical developments following the study of the…
To elucidate the underlying nature of the hidden order (HO) state in heavy-fermion compound URu2Si2, we measure electrical transport properties of ultraclean crystals in a high field/low temperature regime. Unlike previous studies, the…
The nature of order in low-temperature phases of some materials is not directly seen by experiment. Such "hidden orders" (HO) may inspire decades of research to identify the mechanism underlying those exotic states of matter. In insulators,…
Several rare earth magnetic pyrochlore materials are well modeled by a spin-1/2 quantum Hamiltonian with anisotropic exchange parameters Js. For the Er2Ti2O7 material, the Js were recently determined from high-field inelastic neutron…
Theoretical model for magnetic ordering in the heavy-fermion metal URu2Si2 is suggested. The 17.5K transition in this material is ascribed to formation of a spin-density wave, which develops due to a partial nesting between electron and…
Magnetization, specific heat, and electrical resistivity measurements were made on single crystals of the filled skutterudite compound PrOs$_{4}$As$_{12}$. Specific heat measurements indicate an electronic specific heat coefficient $\gamma$…
Heavy fermions have served as prototype examples of strongly-correlated electron systems. The occurrence of unconventional superconductivity in close proximity to the electronic instabilities associated with various degrees of freedom…
We report the crystal structure and highly-anisotropic magnetic, transport and thermal properties of an exceptionally good single crystal of U(Ru0.92Rh0.08)2Si2 prepared using a modified Czochralski method. Our study, that also includes…
For more than two decades, the nonmagnetic anomaly observed around 17.5 K in URu2Si2, has been investigated intensively. However, any kind of fingerprint for the lattice anomaly has not been observed. Therefore, the order has been called…
We performed AC calorimetry and magnetoresistance measurements under pressure for H || a-axis (easy-magnetization axis) in the novel heavy-fermion superconductor UTe2. Thanks to the thermodynamic information, multiple superconducting phases…
We report on muon spin relaxation measurements of the 4f^2-based heavy-fermion superconductor filled-skutterudite PrOs4Sb12. The results reveal the spontaneous appearance of static internal magnetic fields below the superconducting…
We have analyzed heat capacity and thermal conductivity measurements of Sr2RuO4 in the normal and superconducting state and come to the conclusion that an order parameter with nodal lines on the Fermi surface is required to account for the…
We report the results of magnetic, heat-capacity, electrical and magnetoresistance measurements on Ho4RhAl and Er4RhAl, characterized by 3 sites for rare-earths (R). Antiferromagnetic ordering sets in at (T_N =) about 8.8 and 4.0 K…
The ordered hexagonal perovskite Ba2CuTeO6 hosts weakly coupled S=1/2 spin ladders produced by an orbital ordering of Cu2+. The magnetic susceptibility chi(T) of Ba2CuTeO6 is well described by that expected for isolated spin ladders with…