Photodetachment dynamics in an inhomogeneous magnetic field

Abstract

The photodetachment dynamics of negative ions in an inhomogeneous gradient magnetic field is investigated for the first time. The motion of the detached electron becomes much more complicated and interesting due to the influence of the non-uniform magnetic field, and its equations of motion can be expressed in terms of Jacobi elliptic functions. The electron’s trajectory in the plane perpendicular to the magnetic field is not a simple circular motion, but can be a helical curve, a sinusoidal curve, or a balloon-shaped curve, etc. The detached electron can travel along different types of closed orbits to the ionic source, causing the returning electron wave to interfere quantum mechanically with the initial outgoing wave. For different polarized laser light, there are in-phase and anti-phase oscillations in the photodetachment cross section (PCS) of the H $$^{\mathrm {-}}$$ ion in a gradient magnetic field. In particular, we discuss the influence of the magnetic field gradient on the oscillatory structures in the PCS of this system. Our study provides some insight in understanding the electron dynamics in an inhomogeneous magnetic field, which can be used to simulate the motion of planets in astrophysics, and has guiding significance for future experimental research. A family of detached electron trajectories in the inhomogeneous magnetic field. a The trajectories in the x–y–z plane. b The corresponding electron trajectory in the x–y plane.