Evolution of superconductivity and charge order in pressurized RbV₃Sb₅

Abstract

The kagome metals A V 3 Sb 5 ( A = K, Rb, Cs) under ambient pressure exhibit an unusual charge order, from which superconductivity emerges. In this work, by applying hydrostatic pressure using a liquid pressure medium and carrying out electrical resistance measurements for RbV 3 Sb 5 , we find that the charge order becomes suppressed under a modest pressure p c (1.4 GPa < p c < 1.6 GPa), while the superconducting transition temperature T c is maximized. T c is then gradually weakened with further increase of pressure and reaches a minimum around 14.3 GPa, before exhibiting another maximum around 22.8 GPa, signifying the presence of a second superconducting dome. Distinct normal state resistance anomalies are found to be associated with the second superconducting dome, similar to KV 3 Sb 5 . Our findings point to qualitatively similar temperature–pressure phase diagrams in KV 3 Sb 5 and RbV 3 Sb 5 , and suggest a close link between the second superconducting dome and the high-pressure resistance anomalies.