  We consider the critical temperature for superconductivity, defined via the
linear BCS equation. We prove that at weak coupling the critical temperature
for a sample confined to a quadrant in two dimensions is strictly larger than
the one for a half-space, which in turn is strictly larger than the one for
$\mathbb{R}^2$. Furthermore, we prove that the relative difference of the
critical temperatures vanishes in the weak coupling limit.
