Oxygen isotope effect on the superfluid density within the $d-$wave and $s-$wave pairing channels of YBa${}_2$Cu${}_4$O${}_8$

Rustem Khasanov, Alexander Shengelaya, Kazimierz Conder +3

We report on measurements of the oxygen isotope (${}^{16}$O/${}^{18}$O) effect (OIE) on the transition temperature $T_{\mathrm{c}}$ and the zero-temperature in-plane magnetic penetration de…