The Role of Polarization for Bound States in Strong Fields

Abstract

As atomic matter interacts with ultrastrong fields, the bound electrons are polarized and have ionization energies changed by Stark-shifting. The unprecedented range of laser intensities from 1015 W cm−2 to 1024 W cm−2 can take the interaction from the neutral atom to a bare nucleus. We have used an outer, single active electron approximation to calculate the polarization and Stark-shifted binding energy for ultraintense lasers interacting with highly charged ions at intensities from 1014 W cm−2 to 1022 W cm−2. The polarization of the bound state can result in a dipole moment and Stark shift that may be 0.1 e a0 and 50 Eh, respectively. At these high intensities, relativistic effects must also be considered. Across the intensity range of these studies, the magnetic field of the laser does not comparably affect the bound state of the atom; the impact of polarization and Stark shift exceed changes to the bound state wave function and binding energy from including relativity.