Dynamics of diamagnetic Zeeman states ionized by half-cycle pulses
Abstract
We study the dynamical evolution of diamagnetic Zeeman states in hydrogen and sodium atoms ionized by half-cycle pulses. The eigenstates of the combined Coulomb-diamagnetic potential are determined by solving the Schrödinger equation using a grid-based pseudopotential method. We study states with principal quantum number n between 15-20 in the l-mixing regime at a magnetic field of 6 T. Diamagnetic states that are initially localized parallel and perpendicular to the magnetic field are subjected to the electric field of a half-cycle pulse (HCP) and their time evolution is monitored. We calculate the total ionized fraction, and also the spectrum of the ionized photoelectrons, keeping the total momentum transferred by the HCP constant and varying the HCP width. We find differences in both the amount of ionization and the form of the photoelectron spectrum for the two classes of localized states. In the impulsive limit, where the width of the pulse is much smaller than typical time scales in the system, the differences are due to the different initial momentum distributions of the parallel and perpendicular states. For longer pulse widths, we find that ionization is supressed as compared with the impulsive limit. The states localized perpendicular to the magnetic field are found to be much more sensitive to the HCP width than the parallel states, which reflects the fact that the two classes of states interact with different parts of the diamagnetic potential during the HCP.
- Publication:
-
Physical Review A
- Pub Date:
- May 2000
- DOI:
- 10.1103/PhysRevA.61.053410
- Bibcode:
- 2000PhRvA..61e3410R
- Keywords:
-
- 32.60.+i;
- 32.80.Rm;
- Zeeman and Stark effects;
- Multiphoton ionization and excitation to highly excited states