Laser-driven relativistic tunneling from p-states

TL;DR

This paper studies relativistic tunneling ionization from p-states in highly charged ions under strong laser fields, revealing spin asymmetry effects caused by Zeeman splitting and relativistic momentum shifts, with implications for ionization rate dependence on laser intensity.

Contribution

It introduces the first analysis of spin asymmetry in relativistic tunneling ionization from p-states, highlighting the role of angular momentum precession and intensity-dependent effects.

Findings

Spin asymmetry arises from Zeeman splitting and relativistic momentum shifts.

Ionization rate depends on laser intensity and angular momentum projection.

Precession dynamics of angular momentum influence ionization behavior.

Abstract

The tunneling ionization of an electron from a p-state in a highly charged ion in the relativistic regime is investigated in a linearly polarized strong laser field. In contrast to the case of an s-state, the tunneling ionization from the p-state is spin asymmetric. We have singled out two reasons for the spin asymmetry: first, the difference of the electron energy Zeeman splitting in the bound state and during tunneling, and second, the relativistic momentum shift along the laser propagation direction during the under-the barrier motion. Due to the latter, those states are predominantly ionized where the electron rotation is opposite to the electron relativistic shift during the under-the-barrier motion. We have investigated the dependence of the ionization rate on the laser intensity for different projections of the total angular momentum and identified the intensity parameter which governs this behaviour. The significant change of the ionization rate is originated from the different precession dynamics of the total angular momentum in the bound state at high and low intensities.