相关论文: Infrared Conductivity of Elemental Bismuth under P…

Pressure dependence of the thermodynamic critical field $B_{\rm c}$ in elemental indium (In) and tin (Sn) superconductors was studied by means of the muon-spin rotation/relaxation. Pressure enhances the deviation of $B_{\rm c}(T)$ from the…

For some heavy-fermion compounds, it has been suggested that a Fermi-surface-changing Lifshitz transition, which can be driven, e.g., by varying an applied magnetic field, occurs inside the heavy- fermion regime. Here we discuss, based on…

We use synchrotron x-ray diffraction and electrical transport under pressure to probe both the magnetism and the structure of single crystal NiS2 across its Mott-Hubbard transition. In the insulator, the low-temperature antiferromagnetic…

It is demonstrated that the known for a long time transition between the gap and the gapless states in the Abrikosov-Gor'kov theory of a superconductor with paramagnetic impurities is of the Lifshitz type, i.e. of the $2\frac12$ order phase…

The London penetration depth, $\lambda(T)$, was measured in a single crystal V$_{3}$Si. The superfluid density obtained from this measurement shows a distinct signature of two almost decoupled superconducting gaps. This alone is…

We study a two-band Hubbard model using the dynamical mean-field theory combined with the exact diagonalization method. At the electron density $n=2$, a transition from a band-insulator to a correlated semimetal occurs when the on-site…

The Fermi surface can be changed by different external conditions like, e.g., pressure or doping. It can lead to a change in the Fermi surface topology, called as the Lifshitz transition. Here, we briefly describe the Lifshitz transitions…

We report X-ray structural studies of the metal-insulator phase transition in bismuth ferrite, BiFeO3, both as a function of temperature and of pressure (931 oC at atmospheric pressure and ca. 45 GPa at ambient temperature). Based on the…

We study an electronic structure of CeRhSb$_{1-x}$Sn$_x$ system, which displays quantum critical transition from a Kondo insulator to a non-Fermi liquid at $x=0.13$. We provide ultraviolet photoelectron spectra of valence band obtained at…

Lifshitz transition (LT) refers to an abrupt change in the electronic structure and Fermi surface, and is associated to a variety of emergent quantum phenomena. Amongst the LTs observed in known materials, the field-induced LT has been rare…

Superconductivity and topological quantum states are two frontier fields of research in modern condensed matter physics. The realization of superconductivity in topological materials is highly desired, however, superconductivity in such…

Superconducting mechanism mediated by interband exchange Coulomb repulsion is examined in an extended two-band Hubbard models with a wide band crossing the Fermi level and coexisting with a narrower band located at moderately lower energy.…

Pressure represents a clean tuning parameter for traversing the complex phase diagrams of interacting electron systems and as such has proved of key importance in the study of quantum materials. Application of controlled uniaxial pressure…

We introduce a two-band model of three-dimensional nodal line semimetals, the Fermi surface of which at half-filling may form various one-dimensional configurations of different topology. We study the symmetries and "drumhead" surface…

The temperature dependence of conductivity $\sigma (T)$ of a two-dimensional electron system in silicon has been studied in parallel magnetic fields B. At B=0, the system displays a metal-insulator transition at a critical electron density…

We report a room-temperature optical reflectivity study performed on [112]-oriented Cd$_3$As$_2$ single crystals over a broad energy range under external pressure up to 10 GPa. The abrupt drop of the band dispersion parameter…

Pressure induced electronic topological transitions in the wide band gap semiconductor Sb2S3 (Eg = 1.7-1.8 eV) with similar crystal symmetry (SG: Pnma) to its illustrious analog, Sb2Se3, has been studied using Raman spectroscopy,…

To elucidate the pressure evolution of the electronic structure in an antiferromagnetic dimer-Mott (DM) insulator ${\beta}^{\prime}$-(BEDT-TTF)$_2$ICl$_2$, which exhibits superconductivity at 14.2 K under 8 GPa, we measured the polarized…

Electronic transport properties of bismuth nanocontacts are analyzed by means of a low temperature scanning tunneling microscope. The subquantum steps observed in the conductance versus elongation curves give evidence of atomic…

An extended study on PdS is carried out with the measurements of the resistivity, Hall coefficient, Raman scattering, and X-ray diffraction at high pressures up to 42.3 GPa. With increasing pressure, superconductivity is observed…