Scattering of charged particles on two spatially separated time-periodic optical fields

TL;DR

This paper investigates how charged particles transmit through two separated oscillating electric fields, revealing narrow resonances influenced by field parameters and phase differences, with potential applications as precise energy filters.

Contribution

It introduces a quantum mechanical model using Floquet theory to analyze transmission resonances in a two-field setup, highlighting the control of transmission via phase differences.

Findings

Transmission resonances depend on laser field parameters.

Resonances repeat with shifted input energies due to Floquet channels.

Phase difference controls the transmission spectrum's fine structure.

Abstract

We consider a monoenergetic beam of moving charged particles interacting with two separated oscillating electric fields. Time-periodic linear potential is assumed to model the light-particle interaction using a nonrelativistic, quantum mechanical description based on Gordon-Volkov states. Applying Floquet theory, we calculate transmission probabilities as a function of the laser field parameters. The transmission resonances in this Ramsey-like setup are interpreted as if they originated from a corresponding static double-potential barrier with heights equal to the ponderomotive potential resulting from the oscillating field. Due to the opening of new "Floquet channels," the resonances are repeated at input energies when the corresponding frequency is shifted by an integer multiple of the exciting frequency. These narrow resonances can be used as precise energy filters. The fine structure of the transmission spectra is determined by the phase difference between the two oscillating light fields, allowing for the optical control of the transmission.