A Caltech Library Service

Control of concerted back-to-back double ionization dynamics in helium

Larsson, Henrik R. and Tannor, David J. (2021) Control of concerted back-to-back double ionization dynamics in helium. Journal of Chemical Physics, 155 (14). Art. No. 144105. ISSN 0021-9606. doi:10.1063/5.0063056.

[img] PDF - Accepted Version
See Usage Policy.

[img] PDF - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


Double ionization (DI) is a fundamental process that despite its apparent simplicity provides rich opportunities for probing and controlling the electronic motion. Even for the simplest multielectron atom, helium, new DI mechanisms are still being found. To first order in the field strength, a strong external field doubly ionizes the electrons in helium such that they are ejected into the same direction (front-to-back motion). The ejection into opposite directions (back-to-back motion) cannot be described to first order, making it a challenging target for control. Here, we address this challenge and optimize the field with the objective of back-to-back double ionization using a (1 + 1)-dimensional model. The optimization is performed using four different control procedures: (1) short-time control, (2) derivative-free optimization of basis expansions of the field, (3) the Krotov method, and (4) control of the classical equations of motion. All four procedures lead to fields with dominant back-to-back motion. All the fields obtained exploit essentially the same two-step mechanism leading to back-to-back motion: first, the electrons are displaced by the field into the same direction. Second, after the field turns off, the nuclear attraction and the electron–electron repulsion combine to generate the final motion into opposite directions for each electron. By performing quasi-classical calculations, we confirm that this mechanism is essentially classical.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Larsson, Henrik R.0000-0002-9417-1518
Tannor, David J.0000-0001-8806-9480
Additional Information:© 2021 Author(s). Published under an exclusive license by AIP Publishing. Submitted: 11 July 2021 • Accepted: 27 September 2021 • Published Online: 11 October 2021. We are thankful to Daniel Reich for helpful discussions about quantum control algorithms and Norio Takemoto for helpful discussions in the beginning of this project. H.R.L. is thankful to Timm Faulwasser and Karl Worthmann for introducing him to classical optimization problems and algorithms during a summer school of the Studienstiftung des deutschen Volkes. H.R.L. acknowledges financial support from the Fonds der Chemischen Industrie and the Studienstiftung des deutschen Volkes. Financial support from the Israel Science Foundation (Grant No. 1094/16) and the German-Israeli Foundation for Scientific Research and Development (GIF) is gratefully acknowledged. The authors have no conflicts to disclose. Data Availability: The data that support the findings of this study are available from the corresponding author upon reasonable request.
Funding AgencyGrant Number
Fonds der Chemischen IndustrieUNSPECIFIED
Studienstiftung des Deutschen VolkesUNSPECIFIED
Israel Science Foundation1094/16
German-Israeli Foundation for Research and DevelopmentUNSPECIFIED
Issue or Number:14
Record Number:CaltechAUTHORS:20220308-454052000
Persistent URL:
Official Citation:Henrik R. Larsson and David J. Tannor , "Control of concerted back-to-back double ionization dynamics in helium", J. Chem. Phys. 155, 144105 (2021)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:113800
Deposited By: George Porter
Deposited On:09 Mar 2022 16:35
Last Modified:17 Mar 2022 18:12

Repository Staff Only: item control page