Experimental Verification of the Fano Effect

Joachim Keßler

Joachim Keßler, J. Lorenz

An absolute measurement of the electron polarization obtained by photoionization of cesium by circularly polarized light is reported. The measured polarization of 65 \ifmmode\pm\else\textpm\fi{} 15% confirms the prediction made by Fano and the assumptions of Seaton on spin-orbit interaction in photoionization of alkali atoms. They also show that it is possible to construct a photoionization source of polarized electrons without using a polarized atom beam.

A. I. Andryushin, Mikhail Vladimirovich Fedorov

Yuqing Li, Guosheng Feng, Jizhou Wu +5 more

The Fano resonance, with a unique asymmetric line shape, is a well-known manifestation of quantum interference with numerous promising applications for light-harvesting devices. Here we report an experimental observation of the Fano effect in an ultracold atom-molecule coupled system realized by photoassociation near a magnetically tunable $d$-wave Feshbach resonance. Our result shows that, compared to ubiquitous single-peak Fano-type line shapes, the coupled Fano resonances feature a two-peak profile. We develop a theory of coupled Fano resonances which agrees very well with the experimental results. This work may open a new perspective for tuning ultracold collisional interaction using the Fano resonance and studying bound states in continuum.

Vl. V. Kocharovsky, Vl. V. Kocharovsky, S. A. Litvak +2 more

The general Fano-Friedrichs Hamiltonian is diagonalized via a proper extraction of all dressed decaying eigenquasistates with complex eigenquasienergies. Their non-adiabatic crossing is described using the true truncated non-Hermitian Hamiltonian with applications to DC + AC non-steady Stark effect.

Сатанин Аркадий Михайлович, Yong Suk Joe