Two-path interference in the resonance-enhanced few-photon ionization of atoms

TL;DR

This paper explores two-path interference in resonance-enhanced few-photon ionization of lithium atoms, demonstrating control over quantum pathways and phase information through polarization and state preparation, with results matching theoretical models.

Contribution

It introduces a novel experimental setup that manipulates atomic states to observe and analyze quantum interference effects in ionization processes.

Findings

Successful control of interference via polarization states

Agreement between experimental data and numerical simulations

Validation of the two-slit interference model in atomic ionization

Abstract

We investigate the resonance-enhanced few-photon ionization of atomic lithium by linearly polarized light whose frequency is tuned near the 2s-2p transition. Considering the direction of light polarization orthogonal to the quantization axis, the process can be viewed as an atomic "double-slit experiment" where the 2p states with magnetic quantum numbers m_l=+-1 act as the slits. In our experiment, we can virtually close one of the two slits by preparing lithium in one of the two circularly polarized 2p states before subjecting it to the ionizing radiation. This allows us to extract the interference term between the two pathways and obtain complex phase information on the final state. The experimental results show very good agreement with numerical solutions of the time-dependent Schroedinger equation. The validity of the two-slit model is also analyzed theoretically using a time-dependent perturbative approach.