Quantum interference at corners

We show that a radiating atom, or molecule, localised at sub-wavelength distances from a corner arising from the intersection of three planar material surfaces, exhibits novel quantum interference effects. The simplest case arises for a corner formed by the intersection of three perfect conductors, all at right angles. This situation is shown here to give rise to super-radiance and sub-radiance effects that are highly sensitive to the dipole moment orientation and position of the radiating atom or molecule in the vicinity of the corner.