WITHDRAWN: Discovery of New Metallic and Superconducting Phase in GaTa4Se8 Under High Pressure

Abstract

Pressure is a unique thermodynamic variable to explore the phase competitions and novel phases inaccessible at ambient conditions. The resistive switching material GaTa4Se8 displays several quantum phases under pressure, such as Jeff = 3/2 Mott insulator, correlated quantum magnetic metal, and d-wave topological superconductivity, which has recently drawn mounting interest. Using high-pressure Raman, X-ray diffraction, extended X-ray absorption, and transport measurements, together with theoretical calculations, we reveal a remarkably rich phase diagram of this molecular magnetic Mott insulator at pressures up to ~ 68 GPa. In this previously unreached pressure regime, we find, GaTa4Se8 exhibits a new metallic phase whose structural and magnetic properties are clearly distinctive from the lower pressure one. Further, we identify a new superconducting phase in this high-pressure regime below Tc ~ 5.5K. Our discoveries highlight GaTa4Se8 as a unique playground in which novel quantum phases and orders coexist and compete with each other; ranges from Mott insulator to Fermi liquid and exhibits multiple metallic and superconducting states.