Related papers: Hall Number in YbRh2Si2
Spin fluctuations are reported near the magnetic field driven quantum critical point in YbRh2Si2. On cooling, ferromagnetic fluctuations evolve into incommensurate correlations located at q0=+/- (delta,delta) with delta=0.14 +/- 0.04 r.l.u.…
Heavy fermion compounds are complex systems but excellent materials to study quantum criticality with the switch of different ground states. Here a special attention is given on the interplay between magnetic and valence instabilities which…
Heavy fermion metals provide a prototype setting to study quantum criticality. Experimentally, quantum critical points have been identified and studied in a growing list of heavy fermion compounds. Theoretically, Kondo destruction has…
We demonstrate that nearly critical quantum magnetic fluctuations in strongly correlated electron systems can change the Fermi surface topology and also lead to spin charge separation (SCS) in two dimensions. To demonstrate these effects we…
Temperature- and field-dependent Hall effect measurements are reported for YbAgGe, a heavy fermion compound exhibiting a field-induced quantum phase transition, and for two other closely related members of the RAgGe series: a non-magnetic…
Hall conductance $\sigma_{xy}$ as the Chern numbers of the Berry connection in the magnetic Brillouin zone is calculated for a realistic multi band tight-band model of graphene with non-orthogonal basis. It is confirmed that the envelope of…
We show that a Fermi surface reconstruction due to spiral antiferromagnetic order may explain the rapid change in the Hall number as recently observed near optimal doping in cuprate superconductors [Badoux~\textit{et. al.}, Nature…
The electronic structure of (Ce,Yb)CoIn5 has been studied by a combination of photoemission, x-ray absorption and bulk property measurements. Previous findings of a Ce valence near 3+ for all x and of an Yb valence near 2.3+ for x>0.3 were…
We report the results of a low temperature (T >= 50 mK) and high field (H <= 180 kOe) study of the Hall resistivity in single crystals of YbAgGe, a heavy fermion compound that demonstrates field-induced non-Fermi-liquid behavior near its…
In Phys. Rev. Lett. 106, 137002 (2011), A. Hackl and M. Vojta have proposed to explain the quantum critical behavior of YbRh2Si2 in terms of a Zeeman-induced Lifshitz transition of an electronic band whose width is about 6 orders of…
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…
Magnets, with topologically-nontrivial Dirac/Weyl points, have recently attracted significant attention owing to the unconventional physical properties, such as large anomalous Hall effects. However, they typically have a high carrier…
Quantum criticality due to the valence transition in some Yb-based heavy fermion metals has gradually turned out to play a crucial role to understand the non-Fermi liquid properties that cannot be understood from the conventional quantum…
We studied the electronic structure of the heavy fermion compound Yb(Ru$_{1-x}$Rh$_{x}$)$_2$Ge$_2$ with $x=0$ and nominally $x=0.125$ using ARPES and LDA calculations. We find a valence band structure of Yb corresponding to a non-integer…
The Hall effect is a powerful tool for investigating carrier type and density. For single-band materials, the Hall coefficient is traditionally expressed simply by $R_H^{-1} = -en$, where $e$ is the charge of the carrier, and $n$ is the…
\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…
Low-temperature specific-heat measurements on YbRh2Si2 at the second order antiferromagnetic (AF) phase transition reveal a sharp peak at T_N=72 mK. The corresponding critical exponent alpha turns out to be alpha=0.38, which differs…
The existence of multiple energy scales is regarded as a signature of the Kondo breakdown mechanism for explaining the quantum critical behavior of certain heavy fermion compounds, like YbRh$_{2}$Si$_{2}$. The nature of the intermediate…
Weyl semimetals (WSMs) are three-dimensional topological materials that exhibit fascinating properties due to the presence of Weyl nodes in their band structure. However, existing WSMs discovered so far often possess multiple pairs of Weyl…
Temperature- and field-dependent measurements of the Hall effect of pure and 4 % Rh-doped URu$_{2}$Si$_{2}$ reveal low density (0.03 hole/U) high mobility carriers to be unique to the `hidden order' phase and consistent with an itinerant…