By use of the generalized Breit-Wigner formula we find a broad class of non-one-dimensional resonant-tunneling structures of quantum dots or atoms having exponentially high and narrow resistance resonances and conductance zero points. It is shown that in definite cases they correspond to the exponentially narrow backscattering conductance resonances near the levels of quantum dots. As examples, the structures of two, three, and four quantum dots are considered. The possibility of observing the resistance resonances by using the scanning tunneling microscope is discussed.

• Received 16 February 1993

DOI:https://doi.org/10.1103/PhysRevB.48.4586