Large oxygen-isotope shift above the quantum critical point of $Y_{1-x}C{a}_{x}B{a}_{2}C{u}_3{O}_{7-delta}$

John Mann, Pieder Beeli, Guo-meng Zhao

We have studied the oxygen-isotope effect on the superconducting transition temperature $T_c$ in overdoped Y${}_{1-x}$Ca${}_x$Ba${}_2$Cu${}_3$O${}_{7-\delta }$ with $x$ = 0.10, 0.20, and 0…