title: Overlapping resonances interference-induced transparency: the S0 → S2/S1 photoexcitation spectrum of pyrazine.
abstract: The phenomenon of "overlapping resonances interference-induced transparency" (ORIT) is introduced and studied in detail for the S(0) → S(2)/S(1) photoexcitation of cold pyrazine (C(4)H(4)N(2)). In ORIT, a molecule becomes transparent at specific wavelengths due to interferences between envelopes of spectral lines displaying overlapping resonances. An example is the S(2) ↔ S(1) internal conversion in pyrazine where destructive interference between overlapping resonances causes the S(0) → S(2)/S(1) light absorption to disappear at certain wavelengths. ORIT may be of practical importance in multi-component mixtures where it would allow for the selective excitation of some molecules in preference to others. Interference-induced cross section enhancement is also shown.
authors.affiliation: Chemical Physics Theory Group, Department of Chemistry, and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Timur
authors.initials: T
authors.lastname: Grinev
authors.forename: Moshe
authors.initials: M
authors.lastname: Shapiro
authors.forename: Paul
authors.initials: P
authors.lastname: Brumer