  We compute the partition function of $\mathcal N=2$ supersymmetric mixed
dimensional QED on a squashed hemisphere using localization. Mixed dimensional
QED is an abelian gauge theory coupled to charged matter fields at the
boundary. The partition function is a function of the complex gauge coupling
$\tau$, the choice of R-symmetry and the squashing deformation. The
superconformal R-symmetry is determined using the 3-dimensional F-maximization.
The free energy as a function of squashing deformation allows computing
correlation functions that contain the insertion of the energy-momentum tensor.
We compute the 2-point correlation function of the boundary energy-momentum
tensor by differentiating the free energy with respect to the squashing
parameter. We comment on the behaviour of the 2-point function as we change the
complex coupling $\tau$.
