Origin of Unexpected Ir in a Superconducting Candidate SrIrO System Analyzed by Photoelectron Holography.

The reason for the absence of superconductivity in SrIrO was estimated by photoelectron spectra and photoelectron holograms. The analysis of the La photoelectron hologram concluded that La atoms are substituted to Sr sites. Two O 1s peaks were observed and were identified as the oxygens in the IrO and SrO planes by photoelectron holography and density functional theory (DFT) calculations.

Chiral phonons: circularly polarized Raman spectroscopy and ab initio calculations in a chiral crystal tellurium.

Recently, phonons with chirality (chiral phonons) have attracted significant attention. Chiral phonons exhibit angular and pseudoangular momenta. In circularly polarized Raman spectroscopy, the peak split of the mode is detectable along the principal axis of the chiral crystal in the backscattering configuration.

Semiconductor-metal transition in BiSe caused by impurity doping.

Doping a typical topological insulator, BiSe, with Ag impurity causes a semiconductor-metal (S-M) transition at 35 K. To deepen the understanding of this phenomenon, structural and transport properties of Ag-doped BiSe were studied. Single-crystal X-ray diffraction (SC-XRD) showed no structural transitions but slight shrinkage of the lattice, indicating no structural origin of the transition.

Hole doping and chemical pressure effects on the strong coupling superconductor PdTe.

Chemical doping of known superconductors is a probate strategy to test and enhance our understanding of which parameters control the critical temperature Tc and the critical magnetic fields. The transition metal chalcogenide PdTe is considered a conventional type II superconductor but its resilience to magnetic Fe doping is noteworthy. Isoelectronic Ni doping has been performed, but the effects of doping charges into PdTe have been so far unexplored.

Superconductivity in BiSbTeSe(= 1.0 and= 2.0) under pressure.

The crystal structure of BiSbTeSe(BiSbTeSe(= 1.0 and= 2.0)) at 0-29 GPa is investigated through synchrotron x-ray diffraction (XRD) and two structural phase transitions are discovered.

Two Linear Regimes in Optical Conductivity of a Type-I Weyl Semimetal: The Case of Elemental Tellurium.

Employing high-pressure infrared spectroscopy we unveil the Weyl semimetal phase of elemental Te and its topological properties. The linear frequency dependence of the optical conductivity provides clear evidence for metallization of trigonal tellurium (Te-I) and the linear band dispersion above 3.0 GPa.

Superconducting 3-TaSe with Giant In-Plane Upper Critical Fields.

Molecular-beam epitaxy (MBE) enables the stabilization of a nonequilibrium material phase, providing a powerful approach to the exploration of emergent phenomena in condensed-matter research. Here we demonstrate that one of the metallic two-dimensional (2D) materials, TaSe, grown by MBE crystallizes into the pure 3 phase with the self-intercalated Ta atoms, 3-TaSe, which is thermodynamically metastable and does not exist in nature as a pure material phase. Interestingly, the thick-enough 3-TaSe film exhibits a superconducting (SC) critical temperature () of 3.

Superconducting behavior of a new metal iridate compound, SrIr, under pressure.

Herein, we investigated the pressure dependence of electric transport in a new type of superconducting metal iridate compound, SrIr, that exhibits a superconducting transition temperature, T , as high as 6.6 K at ambient pressure, in order to complete the T -pressure (p ) phase diagram. Very recently, this sample's superconductivity was discovered by our group, but the superconducting behavior has not yet been clarified under pressure.

Determination of the local structure of SrMIrO (M = K, La) as a function of doping and temperature.

The local structure of correlated spin-orbit insulator Sr2-xMxIrO4 (M = K, La) has been investigated by Ir L3-edge extended X-ray absorption fine structure measurements. The measurements were performed as a function of temperature for different dopings induced by substitution of Sr with La or K. It is found that Ir-O bonds have strong covalency and they hardly show any change across the Néel temperature.

Observation of current-induced bulk magnetization in elemental tellurium.

The magnetoelectric effect in bulk matter is of growing interest both fundamentally and technologically. Since the beginning of the century, the magnetoelectric effect has been studied intensively in multiferroic materials. However, magnetoelectric phenomena in materials without any (anti-)ferroic order remain almost unexplored.

The electronic structure of AgSnSe (x = 0.0, 0.1, 0.2, 0.25 and 1.0).

We have studied the valence electronic structure of AgSnSe (x = 0.0, 0.1, 0.

Observation of orbital resonance Hall effect in (TMTSF)2ClO4.

We report the observation of a Hall effect driven by orbital resonance in the quasi-1-dimensional (q1D) organic conductor (TMTSF)2ClO4. Although a conventional Hall effect is not expected in this class of materials due to their reduced dimensionality, we observed a prominent Hall response at certain orientations of the magnetic field B corresponding to lattice vectors of the constituent molecular chains, known as the magic angles (MAs). We show that this Hall effect can be understood as the response of conducting planes generated by an effective locking of the orbital motion of the charge carriers to the MA driven by an electron-trajectory resonance.