Manipulating dynamical Rabi-splitting with two-color laser pulses.

H Agueny,Y Adnani,A Taoutioui,A Makhoute

doi:10.1364/oe.27.021020

Abstract

We theoretically investigate strong-field ionization of hydrogen atoms by orthogonally polarized two-color (OTC) laser pulses consisting of a fundamental field that is resonant with the 1s - 2p transition and its second harmonic. Numerical simulations are performed by solving the two-dimensional time-dependent Schrödinger equation and recording the photoelectron momentum distribution. In this strong-field resonant ionization, the atom undergoes many Rabi cycles and the electron can be emitted within a completed Rabi-cycle leading to the splitting of the localized momentum distribution. Here, the splitting is attributed to dynamic Rabi-splitting as a result of the dynamic Stark effect. The employed OTC scheme is shown to be efficient for controlling the dynamic Rabi-splitting through the control of quantum-path interferences involved in one-photon and two-photon absorption processes. The control scheme is accomplished by varying the relative ratio intensity and optical phase between the two pulses, and its footprint is mapped in the momentum distribution. This is shown to lead to an asymmetric distribution and suppression of the ionization process. The obtained results suggest the OTC scheme as a tool for coherent control of dynamic Rabi-oscillations via the controlled quantum-path interferences, thus opening new directions towards designing quantum states via the control OTC scheme.

Highlights

The dynamics of two atomic levels involved in an atomic transition mediated by a coherent resonant laser pulse leads to novel phenomena manifested by their nonlinearity
The light-induced resonant ionization dynamics assisted by a streaking field within the orthogonally polarized two-color (OTC) scheme has been theoretically studied by solving the 2D time-dependent Schrödinguer equation (2D-TDSE)
The dynamics has led to the emergence of dynamic Rabi-splitting in the photoelectron momentum distribution accompanied with an asymmetric ionization profile

Summary

Introduction

The dynamics of two atomic levels involved in an atomic transition mediated by a coherent resonant laser pulse leads to novel phenomena manifested by their nonlinearity. Motivated by general interest of Rabi oscillations as a powerful tool to prepare and manipulate quantum states, we propose in this work a control scheme based on orthogonally polarized two-color (OTC) laser pulses to gain control over the electron dynamics. Introducing this OTC scheme has shown to provide an unprecedented insight into light-induced electronic processes, enabling to coherently control their dynamical behavior. To our knowledge, manipulating Rabi-oscillations by means of the OTC control scheme have not been reported previously It is the purpose of this paper to investigate the photoelectron momentum distribution to learn about ultrafast electron dynamics using OTC laser pulses. Atomic units are used in this article unless otherwise indicated

Theoretical background

Results and discussion

Conclusions