Erratum: Semirelativistic Schrödinger Equation for Relativistic Laser-Matter Interactions [Phys. Rev. Lett. 121, 253202 (2018)].

This corrects the article DOI: 10.1103/PhysRevLett.121.253202.

Semirelativistic Schrödinger Equation for Relativistic Laser-Matter Interactions.

A semirelativistic formulation of light-matter interaction is derived using the so called propagation gauge and the relativistic mass shift. We show that relativistic effects induced by a superintense laser field can, to a surprisingly large extent, be accounted for by the Schrödinger equation, provided that we replace the rest mass in the propagation gauge Hamiltonian by the corresponding time-dependent field-dressed mass. The validity of the semirelativistic approach is tested numerically on a hydrogen atom exposed to an intense extreme ultraviolet laser pulse strong enough to accelerate the electron towards relativistic velocities. It is found that while the results obtained from the ordinary (nonrelativistic) Schrödinger equation generally differ from those of the Dirac equation, demonstrating that relativistic effects are significant, the semirelativistic formulation provides results in quantitative agreement with a fully relativistic treatment.

Scattering in a quantum dot: the role of resonances.

The dynamics of a system in which an electron is incident on a populated quantum dot is studied by resolving the time dependence of the system. Specifically, one electron is initially at rest in the ground state of the dot, whereas the incident electron has a narrow velocity distribution. In addition to the probabilities of reflection and transmission, the probability of excitation is found as a function of energy. Moreover, probabilities of both electrons being ejected or both being captured are obtained. The latter process involves spontaneous emission. It is found that the dynamics is strongly influenced by the presence of doubly excited states; reflection becomes considerably more probable in the energetic vicinity of such states. This, in turn, contributes to an increase in the probability of trapping also the second electron within the dot.

Nonsequential two-photon double ionization of atoms: identifying the mechanism.

We develop an approximate model for the process of direct (nonsequential) two-photon double ionization of atoms. Employing the model, we calculate (generalized) total cross sections as well as energy-resolved differential cross sections of helium for photon energies ranging from 39 to 54 eV. A comparison with results of ab initio calculations reveals that the agreement is at a quantitative level. We thus demonstrate that this complex ionization process can be described by the simple model, providing insight into the underlying physical mechanism. Finally, we use the model to calculate generalized cross sections for the two-photon double ionization of neon in the nonsequential regime.