Coupling Between Electrons and Charge Density Wave Fluctuation and its Possible Role in Superconductivity.

In most charge density wave (CDW) systems of different material classes, ranging from traditional correlated systems in low-dimension to recent topological systems with Kagome lattice, superconductivity emerges when the system is driven toward the quantum critical point (QCP) of CDW via external parameters of doping and pressure. Despite this rather universal trend, the essential hinge between CDW and superconductivity has not been established yet. Here, the evidence of coupling between electron and CDW fluctuation is reported, based on a temperature- and intercalation-dependent kink in the angle-resolved photoemission spectra of 2H-PdTaSe.

Optimized superconductivity in the vicinity of a nematic quantum critical point in the kagome superconductor Cs(VTi)Sb.

CsVSb exhibits superconductivity at T = 3.2 K after undergoing intriguing two high-temperature transitions: charge density wave order at ~98 K and electronic nematic order at T ~ 35 K. Here, we investigate nematic susceptibility in single crystals of Cs(VTi)Sb (x = 0.

Pressure-Dependent Structure of BaZrO Crystals as Determined by Raman Spectroscopy.

The structure of dielectric perovskite BaZrO, long known to be cubic at room temperature without any structural phase transition with variation in temperature, has been recently disputed to have different ground state structures with lower symmetries involving octahedra rotation. Pressure-dependent Raman scattering measurements can identify the hierarchy of energetically-adjacent polymorphs, helping in turn to understand its ground state structure at atmospheric pressure. Here, the Raman scattering spectra of high-quality BaZrO single crystals grown by the optical floating zone method are investigated in a pressure range from 1 atm to 42 GPa.

Experimental signatures of nodeless multiband superconductivity in a [Formula: see text] single crystal.

In order to understand the superconducting gap nature of a [Formula: see text] single crystal with [Formula: see text], in-plane thermal conductivity [Formula: see text], in-plane London penetration depth [Formula: see text], and the upper critical fields [Formula: see text] have been investigated. At zero magnetic field, it is found that no residual linear term [Formula: see text] exists and [Formula: see text] follows a power-law [Formula: see text] (T: temperature) with n = 2.66 at [Formula: see text], supporting nodeless superconductivity.