Experimental evidence for a second superconducting dome in a highly overdoped cuprate under pressure

It has been proposed that a second superconducting dome exists in highly overdoped cuprates [1]. While such overdoped cuprates are not typically structurally stable at ambient conditions, compression increases hole doping beyond the ambient pressure limit. With pressure-induced doping, non-monotonic enhancements in superconducting T_c are reported in the bismuth-bearing cuprates [2]. As Bi₂Sr₂Ca₂Cu₃O_10+δ (Bi-2223) is structurally stable to at least 155 GPa [3] it is an ideal system to study highly overdoped cuprates. We present evidence for the existence of a second superconducting dome upon compression in pressure doped Bi₂Sr₂Ca₂Cu₃O_10+δ, with T_c values greatly exceeding those observed at ambient pressure.

[1] T. H. Geballe and M. Marezio, Physica C 13, 680-684 (2009)

[2] X.J. Chen et al., Nature 466 950-953 (2010)

[3] A.C. Mark et al., Phys. Rev. Mater. 7, 064803 (2023)