Kapitza-Dirac Blockade: A Universal Tool for the Deterministic Preparation of Non-Gaussian Oscillator States

Harmonic oscillators count among the most fundamental quantum systems with important applications in quantum optics, solid-state physics, molecular physics, nanoparticle trapping, and quantum information processing. They are distinguished by their equidistant energy level spacing, a feature that is often desired but also a challenge if the goal is to deterministically populate specific target states. Here, we propose to use the inelastic Kapitza-Dirac effect as a means to solve this challenge. Quantum interference in inelastic Kapitza-Dirac scattering can suppress the sequential climbing of harmonic oscillator states and achieve selective excitation to Schr\"{o}dinger cat states or other non-Gaussian states for a wide range of harmonically trapped particles. We discuss the feasibility of experiments with single electrons, complex molecules, and dielectric nanoparticles.