Related papers: Theoretical Model for the Semimetal Yb_4As_3
e have investigated the magnetic properties of YbRu$_{2}$Ge$_{2}$ by means of magnetic susceptibility $\chi$(T), specific heat C(T) and electrical resistivity $\rho$(T) measurements performed on flux grown single crystals. The Curie-Weiss…
We develop a slave-boson theory for the t-J model at finite doping which respects an SU(2) symmetry -- a symmetry previously known to be important at half filling. The mean field phase diagram is found to be consistent with the phases…
We investigated the magnetic structure and dynamics of YbMnBi$_2$, with elastic and inelastic neutron scattering, to shed light on the topological nature of the charge carriers in the antiferromagnetic phase. We confirm C-type…
A model to describe electronic correlations in energy bands is considered. The model is a generalization of the conventional Hubbard model that allows for the fact that the wavefunction for two electrons occupying the same Wannier orbital…
In our short review, we consider the transport properties of strongly correlated Fermi systems like heavy fermion metals and high-$T_c$ superconductors. Their transport properties are defined by strong inter-particle interaction forming…
We apply a recent quasiparticle model for the electronic properties of metallic helimagnets to calculate the transport properties of three-dimensional systems in the helically ordered phase. We focus on the ballistic regime tau^2 T…
Alkali metals display unexpected properties at high pressure, including emergence of low symmetry crystal structures, that appear to occur due to enhanced electronic correlations among the otherwise nearly-free conduction electrons. We…
A composite model of fermions is proposed to explain the "anomaly" in $Z \rightarrow b {\bar b}$ and, to a lesser extent, in $Z \rightarrow c {\bar c}$. It contains a {\em nonsequential} fourth family whose mass of one member (the charge…
We investigate the magnetic field dependent thermopower, thermal conductivity, resistivity and Hall effect in the heavy fermion metal YbRh2Si2. In contrast to reports on thermodynamic measurements, we find in total three transitions at high…
The recent phase sensitive measurements in the superconducting $B$-phase of UPt$_3$ provide strong evidence for the triplet, chiral $k_z(k_x \pm ik_y)^2$ pairing symmetries, which endow the Cooper pairs with orbital angular momentum…
Results of combined thermal and electrical transport measurements through the magnetic field-induced quantum critical point in the heavy-fermion compound YbRh2Si2 are revisited to explore the relationship between the strange-metal behavior,…
The crystal structure and numerous normal and superconducting state properties of layered tetragonal (P4/nmm) LaFeAsO, with F-doping of 11 %, are reported. Resistivity measurements give an onset transition temperature Tc = 28.2 K, and low…
Electronic structures of the quantum critical superconductor beta-YbAlB4 and its polymorph alpha-YbAlB4 are investigated by using bulk-sensitive hard x-ray photoemission spectroscopy. From the Yb 3d core level spectra, the values of the Yb…
Recent experiments on quantum criticality in the Ge-substituted heavy-electron material YbRh2Si2 under magnetic field have revealed a possible non-Fermi liquid (NFL) strange metal (SM) state over a finite range of fields at low…
We report the synthesis and basic properties of single crystals of a new binary compound, Yb$_{3}$Pt$_{4}$. The Yb ions in this compound are fully trivalent, and heat capacity measurements show that the crystal field scheme involves a…
We investigate the influence of an unoccupied band on the transport properties of a strongly correlated electron system. For that purpose, additional orbitals are coupled to a Hubbard model via hybridization. The filling is one electron per…
Here, we report a systematic study on the Hall-effect of the semi-metallic state of bulk MoTe$_2$, which was recently claimed to be a candidate for a novel type of Weyl semi-metallic state. The temperature ($T$) dependence of the carrier…
We present a systematic study of transport and thermodynamic properties of the Laves phase system Nb$_{1-y}$Fe$_{2+y}$. Our measurements confirm that Fe-rich samples, as well as those rich in Nb (for $\mid y\mid\geq 0.02$), show bulk…
The nature of the Fermi surface observed in the recently discovered family of unconventional insulators starting with SmB$_6$ and subsequently YbB$_{12}$ is a subject of intense inquiry. Here we shed light on this question by comparing…
Sr$_2$RuO$_4$ is an unconventional superconductor with a tetragonal structure, whereas Ca$_2$RuO$_4$ is a Mott insulator with orthorhombic symmetry. The substituted Ca$_{2-x}$Sr$_x$RuO$_4$ has yielded a rich phase diagram that is just…