title: Scattering theory of Bardeen's formalism for tunneling: new approach to near-field microscopy
abstract: We propose a new theoretical approach to near-field microscopy, which allows one to deal with scanning tunneling microscopy and scanning near-field optical microscopy with a unified formalism. Under the approximation of weak tip-sample coupling, we show that Bardeen's perturbation formula, originally derived for electron tunneling, can be derived from a scattering formalism which extends its validity to electromagnetic vector fields. This result should find broad applications in near-field imaging and spectroscopy.
authors.affiliation: Laboratoire d'Energetique Moleculaire et Macroscopique, Combustion, Ecole Centrale Paris, Centre National de la Recherche Scientifique, 92295 Chatenay-Malabry Cedex, France.
authors.initials: R
authors.lastname: Carminati
authors.initials: JJ
authors.lastname: Saenz