Theoretical analysis of channel drop tunneling processes

We investigate general channel drop tunneling processes using both analytic theory and first-principles simulations. These tunneling processes occur when two one-dimensional continuums are brought into close proximity with a resonator system that supports localized states. Propagating states can be transferred between the continuums through the resonator system. We show that the transport properties are intricately related to the symmetries of the resonant states. Complete transfer can be achieved by manipulating the symmetries of the system, and by forcing an accidental degeneracy between states with different symmetries. In addition, the line shape of the transfer spectrum can be engineered by varying the number of localized states in the resonator system. The theoretical analysis is confirmed by first-principles simulations of transport properties in a twodimensional photonic crystal. @S0163-1829~99!09419-9#