LOCAL SUPPRESSION OF SUPERCONDUCTIVITY IN ZN-SUBSTITUTED HIGH T-C CUPRATES

The strong suppression of T-c in high T-c cuprate superconductors (HTS Cs) is often described with a mean-field (MF) pair-breaking model. Her e, we present mu SR data which show that this picture fails to describ e simultaneously the dependences of T-c and n(s)/m (superconducting c arrier density/effective mass) on Y-ab, the planar density of Zn impur ities. Instead, the experimental results are very well described by a ''Swiss-cheese'' model, where carriers within an ab-plane coherence le ngth xi(ab) around each Zn are excluded from the superfluid, resulting in the reduction of n(s). [1].