Near-field optical interactions with semiconductor quantum structures
Quantum dots are semiconductor structures that confine the electrons and holes to a volume of the order of 20 cubic nanometers. These structures are similar to atoms, but they are more than an order of magnitude larger. Therefore, using nanoscale techniques it is feasible to manipulate their quantum wave functions. With this ability, promising applications can be developed, such as quantum logic gates.
We are interested in understanding the interaction of a quantum dot with an optical near-field. The tip enhancement technique produces an electric field with sufficiently strong gradients that allow the excitation of higher order transitions such as magnetic dipole or electric quadrupole transitions.

Quantum electrodynamics of optical near-fields
Under certain circumstances where matter is present, evanescent waves may arise. These evanescent waves interact with atoms, modifying their radiative properties. So far, the quantum mechanical description of such interactions has been limited to special cases. The medium is assumed to behave macroscopicaly by characterizing it with a refractive index. Our project is to find a general description of the interaction of evanescent fields without using macroscopic approximations.