### Abstract

We present a theory for controlling the dynamics of a dissipative, quantum system with a laser field optimized locally in time. The theory is applicable to both weak and strong field control of the quantum dynamics. The theoretical groundwork is based on the equation of motion of the density matrix in Liouville space. Interactions between the molecules and the heat bath are taken into account within a Markov approximation. The derivation of the locally optimized laser field in a feedback form is based on the local optimization theory in the Hilbert space, proposed in a previous paper [M. Sugawara and Y. Fujimura, J. Chem. Phys. 100, 5646 (1994)]. The theory is applied to a simple, two-level quantum system with a dephasing constant. We present both the calculated time evolution of the off-diagonal density matrix element and that of the population of the states in the optimized laser field. These calculations show that the control of the system by the laser field is sufficient to avoid the dephasing effects. We discuss how the dephasing dynamics affects the optimization of the laser field.

Original language | English |
---|---|

Pages (from-to) | 6586-6592 |

Number of pages | 7 |

Journal | The Journal of Chemical Physics |

Volume | 101 |

Issue number | 8 |

Publication status | Published - 1994 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics

### Cite this

*The Journal of Chemical Physics*,

*101*(8), 6586-6592.

**Control of a quantum dynamics by a locally optimized laser field. II. Application to a system with dissipation.** / Sugawara, Michihiko; Fujimura, Y.

Research output: Contribution to journal › Article

*The Journal of Chemical Physics*, vol. 101, no. 8, pp. 6586-6592.

}

TY - JOUR

T1 - Control of a quantum dynamics by a locally optimized laser field. II. Application to a system with dissipation

AU - Sugawara, Michihiko

AU - Fujimura, Y.

PY - 1994

Y1 - 1994

N2 - We present a theory for controlling the dynamics of a dissipative, quantum system with a laser field optimized locally in time. The theory is applicable to both weak and strong field control of the quantum dynamics. The theoretical groundwork is based on the equation of motion of the density matrix in Liouville space. Interactions between the molecules and the heat bath are taken into account within a Markov approximation. The derivation of the locally optimized laser field in a feedback form is based on the local optimization theory in the Hilbert space, proposed in a previous paper [M. Sugawara and Y. Fujimura, J. Chem. Phys. 100, 5646 (1994)]. The theory is applied to a simple, two-level quantum system with a dephasing constant. We present both the calculated time evolution of the off-diagonal density matrix element and that of the population of the states in the optimized laser field. These calculations show that the control of the system by the laser field is sufficient to avoid the dephasing effects. We discuss how the dephasing dynamics affects the optimization of the laser field.

AB - We present a theory for controlling the dynamics of a dissipative, quantum system with a laser field optimized locally in time. The theory is applicable to both weak and strong field control of the quantum dynamics. The theoretical groundwork is based on the equation of motion of the density matrix in Liouville space. Interactions between the molecules and the heat bath are taken into account within a Markov approximation. The derivation of the locally optimized laser field in a feedback form is based on the local optimization theory in the Hilbert space, proposed in a previous paper [M. Sugawara and Y. Fujimura, J. Chem. Phys. 100, 5646 (1994)]. The theory is applied to a simple, two-level quantum system with a dephasing constant. We present both the calculated time evolution of the off-diagonal density matrix element and that of the population of the states in the optimized laser field. These calculations show that the control of the system by the laser field is sufficient to avoid the dephasing effects. We discuss how the dephasing dynamics affects the optimization of the laser field.

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UR - http://www.scopus.com/inward/citedby.url?scp=36449004672&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:36449004672

VL - 101

SP - 6586

EP - 6592

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 8

ER -