Pressure-induced double superconducting domes and charge instability in the kagome metal KV3Sb5

The kagome metal KV3Sb5 hosts charge order, topologically nontrivial Dirac band crossings, and a super-conducting ground state with unconventional characteristics, providing an ideal platform to investigate the interplay between different electronic states on the kagome lattice. Here we study the evolution of charge order and superconductivity in KV3Sb5 under hydrostatic pressure using electrical resistivity measurements. With the application of pressure, the superconducting transition temperature T-c = 0.9 K under ambient pressure quickly increases to 3.1 K at p = 0.4 GPa, as charge order progressively weakens. Upon further increasing pressure, signatures of charge order disappear at p(c1) approximate to 0.5 GPa and Tc is gradually suppressed, forming a superconducting dome that terminates at p approximate to 10 GPa. Beyond p approximate to 10 GPa, a second superconducting dome emerges with maximum T-c approximate to 1.0 K at p(c2) approximate to 22 GPa, which becomes fully suppressed at p approximate to 28 GPa. The suppression of superconductivity for the second superconducting dome is associated with the appearance of a unique high-pressure phase, possibly a distinct charge order.

Automated summary

The study on KV3Sb5 reveals that with increasing pressure, the charge order progressively weakens and the superconducting transition temperature undergoes different degrees of changes. A superconducting dome is formed at around 10 GPa, while a smaller superconducting dome emerges beyond 10 GPa.