Reply: Josephson effect and a π-state in superfluid 3He

Backhaus et al. reply - Avenel et al. have suggested a mechanism that might explain the recently discovered metastable π-state in a superfluid ³He weak-link array. We are pleased that our experiment is leading to new ideas that may extend the understanding of weak-link arrays. We agree with Avenel et al.'s comment that, when the individual apertures are in a (short coherence length, low temperature) hysteretic regime, collective phenomena quite distinct from single weak-link behaviour might be observed. Nevertheless, in the temperature regime in which the coherence length is comparable to the aperture dimensions, we have shown that the collective behaviour of the array is similar to that of a single weak link,.