Pinning Pair-Density-Wave Superconductivity about Zn Impurities in a Cuprate

In studying stripe-ordered La_1.905Ba_0.095CuO₄ with superconducting T_c = 32 K, we have previously shown that both a c-axis magnetic field and 1% Zn doping enhance the spin-stripe order [1]. The magnetic field also causes a decoupling of the superconducting CuO₂ layers [2]. We now have evidence for a similar decoupling induced by Zn, based on measurements of anisotropic resistivity and magnetic susceptibility [3]. The observations are consistent with a local pinning of pair-density-wave superconducting order [4] by the Zn impurities, thus frustrating the interlayer Josephson coupling. Our results have implications for the interpretation of STM measurements of quasiparticle interference in terms of the pairing gap.
[1] J.S. Wen et al., Phys. Rev. B 85, 134512 (2012).
[2] J.S. Wen et al., Phys. Rev. B 85, 134513 (2013).
[3] P.M. Lozano et al., arXiv:2010.00610.
[4] D.F. Agterberg et al., Annu. Rev. Condens. Matter Phys. 11, 231 (2020).