A recent experiment by Ma and collaborators shows that the gap anisotropy in ${ \rm Bi}_2 { \rm Sr}_2 { \rm Ca}_1 { \rm Cu}_2 { \rm O}_{ 8+x}$ is strongly temperature dependent. In particular, the superconducting gap along the $\Gamma - M$ direction shows a weaker temperature dependence than the gap along the $\Gamma - X$ direction which decreases rapidly with temperature. We explain this novel feature as a natural consequence of the interlayer tunneling mechanism of superconductivity.
Categories: cond-mat