Laser enhanced auto-ionization and dressed resonances

Joseph W. Haus, Kazimierz Rza̧żewski, Joseph H. Eberly

Nikolai B. Delone, В. П. Крайнов

Joseph H. Eberly, Dan Agassi

We describe the strong field dressing of atomic resonance states, and apply the dressed state description to the photo-excitation of an auto-ionizing resonance, including the effects of radiative and purely transverse line broadenings.

K. L. Litvinenko

The ordinary Fano effect occurs in many-electron atoms and requires an auto-ionizing state.With such a state, photo-ionization may proceed via pathways that interfere, and the characteristicasymmetric resonance structures appear in the continuum. Here we demonstrate that Fano structure15may also be induced without need of auto-ionization, by dressing the continuum with an ordinarybound state in any atom by a coupling laser. Using multi-photon processes gives complete, ultra-fastcontrol over the interference. We show that a line-shape indexqnear unity (maximum asymmetry)may be produced in hydrogenic silicon donors with a relatively a weak beam. Since the Fanolineshape has both constructive and destructive interference, the laser control opens the possibility20of state-selective detection with enhancement on one side of resonance and invisibility on the other.We discuss a variety of atomic and molecular spectroscopies, and in the case of silicon donors weprovide a calculation for a qubit readout application

Nikolai B. Delone, В. П. Крайнов

K. L. Litvinenko, Nguyen H. Le, Britta Redlich +5 more

The ordinary Fano effect occurs in many-electron atoms and requires an autoionizing state. With such a state, photo-ionization may proceed via pathways that interfere, and the characteristic asymmetric resonance structures appear in the continuum. Here we demonstrate that Fano structure may also be induced without need of auto-ionization, by dressing the continuum with an ordinary bound state in any atom by a coupling laser. Using multi-photon processes gives complete, ultra-fast control over the interference. We show that a line-shape index q near unity (maximum asymmetry) may be produced in hydrogenic silicon donors with a relatively weak beam. Since the Fano lineshape has both constructive and destructive interference, the laser control opens the possibility of state-selective detection with enhancement on one side of resonance and invisibility on the other. We discuss a variety of atomic and molecular spectroscopies, and in the case of silicon donors we provide a calculation for a qubit readout application.