@article {li2003quantum,
	title = {Quantum multiple scattering: Eigenmode expansion and its applications to proximity resonance},
	journal = {Physical Review A},
	volume = {67},
	year = {2003},
	pages = {032712},
	publisher = {APS},
	abstract = {We show that for a general system of N s-wave point scatterers, there are always N eigenmodes. These eigenmodes or eigenchannels play the same role as spherical harmonics for a spherically symmetric target{\textemdash}they give a phase shift only. In other words, the T matrix of the system is of rank N, and the eigenmodes are eigenvectors corresponding to nonzero eigenvalues of the T matrix. The eigenmode expansion approach can give insight to the total scattering cross section; the position, width, and superradiant or subradiant nature of resonance peaks; the unsymmetric Fano line shape of sharp proximity resonance peaks based on the high-energy tail of a broadband; and other properties. Off-resonant eigenmodes for identical proximate scatterers are approximately angular-momentum eigenstates.},
	author = {Li, Sheng and Heller, EricJ.}
}
