Quantum Optics in the Near-Field |
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.