Semiclassical states for the curl-curl problem

We show the existence of the so-called semiclassical states $\mathbf{U}:\mathbb{R}^3\to\mathbb{R}^3$ to the following curl-curl problem $$\varepsilon^2\; \nabla \times (\nabla \times \mathbf{U}) + V(x) \mathbf{U} = g(\mathbf{U}),$$ for sufficiently small $\varepsilon > 0$. We study the asymptotic behaviour of solutions as $\varepsilon\to 0^+$ and we investigate also a related nonlinear Schr\"odinger equation involving a singular potential. The problem models large permeability nonlinear materials satisfying the system of Maxwell equations.