Stark states at the continuum boundary

Joseph Frederick Baugh

Béla Gazdy

Alexander V. Glushkov, Ya. I. Lepikh, О. Yu. Khetselius +3 more

A numerical calculation of the DC Stark effect for hydrogen and sodium atoms and Wannier-Mott excitons in an external uniform DC electric field is carried out within the operator perturbation theory method. New adequate model for description of the unique especialitites in the photoionization spectra of the hydrogenic atoms is proposed. It is found that the Stark shift for the n=2 state of excitons in the Cu2 O semiconductor (yellow series) at the electric field strength 600 V/cm results in — 3,1 10 -4 eV which agrees well with experimental data of Gross et al. It is indicated also that the analogous unique especialitites may possibly take a place in the Wannier-Mott excitons spectra near the threshold boundary

J. M. Lecomte, Eliane Luc-Koenig

The long-range diamagnetic interaction arising from the Earth's magnetic field produces a striking change in the photoionisation Stark spectra. The profiles of the supplementary resonances observed for the excited sodium atoms are typical of continuum-continuum state mixing.

В. В. Колосов

Daniel Braak, Lei Cong, Hans-Peter Eckle +2 more

The Rabi–Stark model is a nonlinear generalization of the quantum Rabi model including the dynamical Stark shift as a tunable term, which can be realized via quantum simulation on a cavity QED platform. When the Stark coupling becomes equal to the mode frequency, the spectrum changes drastically, a transition usually termed “spectral collapse” because numerical studies indicate an infinitely degenerate ground state. We show that the spectrum extends continuously from a threshold value up to infinity. A set of normalizable states is embedded in the continuum, which furnishes an unexpected analogy to the atomic Stark effect. Bound states and continuum can be obtained analytically through two equally justified but different confluence processes of the associated differential equation in Bargmann space. Moreover, these results are obtained independently using a method based on adiabatic elimination of the spin degree of freedom and corroborated through large-scale numerical checks.