Related papers: Comparison of structural transformations and super…
We report the first observation of a pressure-induced transition from a superconducting (SC) to an insulating (I) phase in single-crystal Ba1-xKxBiO3 (x = 0.4, 0.43, 0.52, and 0.58) superconductors. X-ray diffraction measurements conducted…
The optical properties of the superconducting single crystal Rb$_{0.8}$Fe$_{1.68}$Se$_2$ with $T_{c}$ $\simeq$ 31 K have been measured over a wide frequency range in the $ab$ plane. We found that the optical conductivity is dominated by a…
Structural stability of paramagnetic (PM) body-centered cubic (bcc) Fe under pressure is investigated based on first-principles phonon calculations. Spin configurations of the PM phase are approximated using a binary special quasi-random…
Pressure dependence of the electronic and crystal structures of K$_{x}$Fe$_{2-y}$Se$_{2}$, which has pressure-induced two superconducting domes of SC I and SC II, was investigated by x-ray emission spectroscopy and diffraction. X-ray…
We report a detailed study of specific heat, electrical resistivity and thermal expansion in combination with inelastic neutron and inelastic X-ray scattering to investigate the origin of superconductivity in the two silicon clathrate…
The superconducting transition in the layered organic compound \alpha-(BEDT-TTF)_2KHg(SCN)_4 has been studied in the two hydrostatic pressure regimes where a charge-density wave is either present or completely suppressed. Within the…
The BCS-BEC crossover from strongly overlapping Cooper pairs to non-overlapping composite bosons in the strong coupling limit has been a long-standing issue of interacting many-body fermion systems. Recently, FeSe semimetal with hole and…
It is known that in pressurized H2S the complex electronic structure in the energy range of 200 meV near the chemical potential can be separated into two electronic components, the first characterized by steep bands with a high Fermi…
Hydrogen-rich compounds have been extensively studied both theoretically and experimentally in the quest for novel high-temperature superconductors. Reports on sulfur-hydride attaining metallicity under pressure and exhibiting…
We report an unusual evolution of superconductivity (SC) in the three-dimensional Dirac semimetal PdTe with increasing pressure up to $\sim$50 GPa. The compressed PdTe exhibits a sudden reversal in the superconducting transition temperature…
FeSe with the PbO structure is a key member of the family of new high-$T_c$ iron pnictide and chalcogenide superconductors, as while it possesses the basic layered structural motif of edge-sharing distorted FeSe$_4$ tetrahedra, it lacks…
Superconductivity in the C32 compounds CaAlSi and SrAlSi is investigated by heat capacity (Cp) measurements as well as high-pressure ac-susceptibility experiments. The heat capacity in the superconducting state is well explained by the BCS…
Since the discovery of high-temperature superconductivity in the thin-film FeSe/SrTiO$_3$ system, iron selenide and its derivates have been intensively scrutinized. Using ab initio density functional theory calculations we review the…
Chromium (Cr) is a transition metal element with 3$d$ orbital electrons. In most compounds containing Cr, due to the correlation effect, twofold features of localization and itinerancy are expected. The localization gives rise to a magnetic…
Two recent experiments [M. Somayazulu $et$ $al$., Phys. Rev. Lett. ${\bf 122}$, 027001 (2019) and A. P. Drozdov $et$ $al$., Nature ${\bf 569}$, 528 (2019)] reported the discovery of superconductivity in the fcc phase of LaH$_{10}$ at a…
Thermoelectric (Bi1-x Sbx)2Te3 (BST-x) compounds with x=0.2, 0.7 and 0.9 have been studied using synchrotron angle-dispersive powder x-ray diffraction in a diamond anvil cell up to 25 GPa (at room temperature). The results clearly indicate…
Using density functional theory the atomic and electronic structure of sodium are predicted to depart substantially from those expected of simple metals for $r_s <$ 2.48 ($p > 130$ GPa). Newly-predicted phases include those with low…
Inspired by recent predictions of superconductivity in B-C framework clathrates, we employ density functional theory to explore potential superconductors among hexagonal hydride-substituted compounds with compositions XB$_8$C, XB$_7$C$_2$,…
Single crystal synchrotron X-ray diffraction as a function of temperature and pressure has revealed a complex biphase mixture in superconducting FeSe. Based on our experimental results we construct a phase diagram where structural behavior…
We report a detailed study of specific heat, electrical resistivity and optical spectroscopy in the superconducting boride LuB12 (Tc = 0.4 K) and compare it to the higher Tc compound ZrB12 (Tc = 6 K). Both compounds have the same structure…