  This paper has been withdrawn and superseded by a new version entitled
"Singularity of the London penetration depth at quantum critical points in
superconductors" by Debanjan Chowdhury, Brian Swingle, Erez Berg and Subir
Sachdev, posted in arXiv:1305.2918. The more recent paper has a number of new
interesting results and includes a comprehensive analysis of 3 different
classes of QCPs, including the one that was originally considered.

Strongly Correlated Electrons;Superconductivity;High Energy Physics - Theory