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Title: Control by decoherence: weak field control of an excited state objective

Abstract

Coherent control employing a broadband excitation is applied to a branching reaction in the excited state. In a weak field for an isolated molecule, a control objective is only frequency dependent. This means that phase control of the pulse cannot improve the objective beyond the best frequency selection. Once the molecule is put into a dissipative environment a new timescale emerges. In this study, we demonstrate that the dissipation allows us to achieve coherent control of branching ratios in the excited state. The model studied contains a nuclear coordinate and three electronic states: the ground and two coupled diabatic excited states. The influence of the environment is modeled by the stochastic surrogate Hamiltonian. The excitation is generated by a Gaussian pulse where the phase control introduced a chirp to the pulse. For sufficient relaxation, we find significant control in the weak field depending on the chirp rate. The observed control is rationalized by a timing argument caused by a focused wavepacket. The initial non-adiabatic crossing is enhanced by the chirp. This is followed by energy relaxation which stabilizes the state by having an energy lower than the crossing point.

Authors:
 [1];  [2];  [1]
  1. Hebrew University of Jerusalem, (Israel)
  2. Northwestern Univ., Evanston, IL (United States)
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Center for Bio-Inspired Energy Science (CBES)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Contributing Org.:
Fritz Haber Research Center for Molecular Dynamics, (Israel)
OSTI Identifier:
1065498
DOE Contract Number:  
SC0000989
Resource Type:
Journal Article
Journal Name:
New Journal of Physics
Additional Journal Information:
Journal Volume: 12; Journal Issue: 1; Related Information: CBES partners with Northwestern University (lead); Harvard University; New York University; Pennsylvania State University; University of Michigan; University of Pittsburgh
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; catalysis (homogeneous), solar (photovoltaic), bio-inspired, charge transport, mesostructured materials, materials and chemistry by design, synthesis (novel materials), synthesis (self-assembly)

Citation Formats

Katz, Gil, Ratner, Mark A., and Kosloff, Ronnie. Control by decoherence: weak field control of an excited state objective. United States: N. p., 2010. Web. doi:10.1088/1367-2630/12/1/015003.
Katz, Gil, Ratner, Mark A., & Kosloff, Ronnie. Control by decoherence: weak field control of an excited state objective. United States. https://doi.org/10.1088/1367-2630/12/1/015003
Katz, Gil, Ratner, Mark A., and Kosloff, Ronnie. 2010. "Control by decoherence: weak field control of an excited state objective". United States. https://doi.org/10.1088/1367-2630/12/1/015003.
@article{osti_1065498,
title = {Control by decoherence: weak field control of an excited state objective},
author = {Katz, Gil and Ratner, Mark A. and Kosloff, Ronnie},
abstractNote = {Coherent control employing a broadband excitation is applied to a branching reaction in the excited state. In a weak field for an isolated molecule, a control objective is only frequency dependent. This means that phase control of the pulse cannot improve the objective beyond the best frequency selection. Once the molecule is put into a dissipative environment a new timescale emerges. In this study, we demonstrate that the dissipation allows us to achieve coherent control of branching ratios in the excited state. The model studied contains a nuclear coordinate and three electronic states: the ground and two coupled diabatic excited states. The influence of the environment is modeled by the stochastic surrogate Hamiltonian. The excitation is generated by a Gaussian pulse where the phase control introduced a chirp to the pulse. For sufficient relaxation, we find significant control in the weak field depending on the chirp rate. The observed control is rationalized by a timing argument caused by a focused wavepacket. The initial non-adiabatic crossing is enhanced by the chirp. This is followed by energy relaxation which stabilizes the state by having an energy lower than the crossing point.},
doi = {10.1088/1367-2630/12/1/015003},
url = {https://www.osti.gov/biblio/1065498}, journal = {New Journal of Physics},
number = 1,
volume = 12,
place = {United States},
year = {Fri Jan 01 00:00:00 EST 2010},
month = {Fri Jan 01 00:00:00 EST 2010}
}