2024/11/07 by Chen, Bijuan, Gu, Yuhao, Wang, Dong +20
#FOS: Physical sciences #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2411.04407
We report pressure-induced superconductivity in the spinel CuIr2S4 with a transition temperature Tc reaching 18.2 K, establishing a new record for this class of materials and surpassing the decades-old limit of 13.7 K. Our electrical transport and synchrotron X-ray diffraction studies up to 224 GPa reveal the emergence of two distinct superconducting phases from a charge-ordered insulating state. The first phase (SC-I) appears around 18 GPa, forming a superconducting dome that peaks at 18.2 K at 133 GPa. Above 111.8 GPa, a second, lower-Tc phase (SC-II) emerges and coexists with SC-I over a broad pressure range. These superconducting phases are intimately linked to a cascade of structural transitions that systematically distort the frustrated pyrochlore lattice of Ir atoms. Our results redefine the potential for superconductivity in spinels and showcase a pathway to high-Tc pairing directly from a correlated insulating state driven by lattice tuning.