Optimal control of photoelectron emission by realistic waveforms

TL;DR

This paper demonstrates how realistic shaped laser waveforms can optimize photoelectron emission in a hydrogen model, significantly increasing electron yield and energy cutoff through quantum control techniques.

Contribution

It introduces a method to control photoelectron emission using experimentally feasible multicolor waveforms optimized via quantum control theory.

Findings

Optimal waveforms extend electron energy cutoff by 50%.

Electron yield increases by several orders of magnitude.

Mixing spectral channels reduces intensity requirements.

Abstract

Recent experimental techniques in multicolor waveform synthesis allow the temporal shaping of strong femtosecond laser pulses with applications in the control of quantum mechanical processes in atoms, molecules, and nanostructures. Prediction of the shapes of the optimal waveforms can be done computationally using quantum optimal control theory (QOCT). In this work we demonstrate the control of above-threshold photoemission of one-dimensional hydrogen model with pulses feasible for experimental waveform synthesis.By mixing different spectral channels and thus lowering the intensity requirements for individual channels, the resulting optimal pulses can extend the cutoff energies by at least up to 50\% and bring up the electron yield by several orders of magnitude. Insights into the electron dynamics for optimized photoelectron emission are obtained with a semiclassical two-step model.