Electronic structures and photoemission spectroscopy

Abstract:

Kagome materials have been reported to possess abundant and peculiar physical properties, which provide an excellent platform to explore exotic quantum states. We present a discovery of superconductivity in van der Waals material Pd _3 P _2 S _8 composed of Pd kagome lattice under pressure. Pd _3 P _2 S _8 displays superconductivity for those pressures where the semiconducting-like temperature dependence of the resistivity turns into a metallic one. Moreover, it is found that the increased pressure results in a gradual enhancement of superconducting transition temperature, which finally reaches 6.83 K at 79.5 GPa. Combining high-pressure x-ray diffraction, Raman spectroscopy and theoretical calculations, our results demonstrate that the observed superconductivity induced by high pressure in Pd _3 P _2 S _8 is closely related to the formation of amorphous phase, which results from the structural instability due to the enhanced coupling between interlayer Pd and S atoms upon compression