Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics B Atomic Molecular and Optical Physics

Effect of phase coherence on population transfer in three harmonic laser pulses

Ying‐Yu Niu, Rong Wang, Ming‐Hui Qiu, Jun-Ling Xiu, Yong‐Chang Han

Published Sep 19, 2017• 5 citations
Publisher

Abstract

Abstract The population transfer controlled by fundamental, 2nd-harmonic and 3rd-harmonic pulses is investigated by using the time-dependent quantum wave packet method. By varying the phase ϕ 1 of the fundamental pulse, it can be coherent with the 2nd-harmonic and 3rd-harmonic pulses. Compared with two harmonic pulses, the phase ϕ 1 in three harmonic pulses is more efficient in controlling population transfer. Molecular orientation can be controlled by the phases of the three pulses. The value of molecular orientation mainly depends on the phase coherence between the fundamental and 2nd-harmonic pulses.

DOI
10.1088/1361-6455/aa8d9d

Related papers

The extended “ladder” transition controlled by two harmonic pulses

Niu Ying-Yu, Rong Wang, Qiu Ming-Hui +1 more

The extended “ladder” transition controlled by two harmonic pulses is investigated by using a time-dependent quantum wave packet method. The molecular population transfers from the state|0, 0> angle to the states|5, 0> angle and|5, 2> angle induced by the fundamental and second-harmonic pulses, and to the states|5, 3> angle and |6, 2> angle induced by the fundamental and third-harmonic pulses. The calculated results show that the two harmonic pulses can induce a nearly 100% of population to transfer to the target state. The relative phase of two pulses can affect the population distribution. The variation of population has a period of π for the fundamental and second-harmonic pulses, and a period of 2π for the fundamental and third-harmonic pulses.

Acta Physica Sinica•Jan 1, 2016•0 citations

Population transfer through multiple channels in two harmonic laser pulses

Rong Wang, Ying‐Yu Niu

The processes of population transfer in the ground electronic state of HCl molecule through the three transition schemes are investigated by numerically solving the time-dependent Schrödinger equation. Two harmonic pulses are employed to induce population transfer and the relative phase of the two pulses can control the final population distributions. In the ladder transition scheme, the variation range of the target population with the relative phase is nearly 100% which is larger than that in the multi-photon transition scheme. It is more efficient for the mixed transition scheme to control population transfer between the initial and target states by using the relative phase. Comparing with the multi-photon and ladder schemes, the transition probability of the target population is more sensitive to the two pulse amplitudes in the mixed transition scheme.

Journal of Theoretical and Computational Chemistry•May 15, 2020•1 citation

Rovibrational population transfer in the ground state controlled by two coherent laser pulses

Rong Wang, Ying‐Yu Niu, Ming‐Hui Qiu +1 more

A time-dependent quantum wave-packet method is employed to investigate the rovibrational dynamics of population transfer in the ground electronic state controlled by two-color ($\ensuremath{\omega}+2\ensuremath{\omega}$) pulses analogous to coherently control the processes of ionization and dissociation. The population can be transferred to three target states, $|4,1\ensuremath{\rangle},\phantom{\rule{0.16em}{0ex}}|0,1\ensuremath{\rangle}$, and $|4,0\ensuremath{\rangle}$, at the same time through the ladder $\ensuremath{\Lambda}$ and multiphoton transitions. With the variation of the relative phase between $\ensuremath{\omega}$ and $2\ensuremath{\omega}$ pulses, the population distributions show oscillation behavior with a period of $\ensuremath{\pi}$. The population variation with relative phase depends on the size of the electric field asymmetry. The probabilities transferred to different target states can be controlled by varying the pulse amplitudes.

Physical Review A•Jan 5, 2015•10 citations

Phase control over decaying molecular states in intense laser pulses

Alexander I. Pegarkov

A time-dependent approach to study phase control over molecular photoabsorption, provided by intense laser pulses, is elaborate. The method allows for the decay linewidth of molecular states and frequency bandwidth of the controlling laser field, and can be applied in weak and strong laser fields where the perturbation theory is invalid. It is shown that a frequency mismatch between the fundamental laser wave and its third harmonic can destroy control. For the example of the one-photon versus three-photon control a simple picture of interference from two monochromatic absorption pathways is not enough to explain phase control and one needs to consider a nonlinear temporal interference of multiquantum transitions. In the perturbation-theory limit an elegant generalization of the famous Shapiro-Hepburn-Brumer equation for the one-photon versus three-photon control is derived. Various numerical calculations illustrate the dependence of phase control on molecular linewidth, fundamental laser wavelength, pulse duration, and peak intensity. It is obtained, that the one-photon versus three-photon control is productive if the molecular state populations, individually produced by each laser wave, have beats of approximately the same frequency. The calculations demonstrate that an enough intense optical pulse can suppress molecular decay and may be used in order to keep stable the state population of a decaying molecule for a long time. The available experimental results for the one-photon versus three-photon control over simple and large polyatomic molecules are analyzed and recommendations for the experimental improvement of control are formulated.

The Journal of Chemical Physics•Sep 8, 2005•2 citations

Phase control in coherent population distribution in molecules

Avijit Datta

A chirped laser pulse transfers population from one level to another level accessible by one photon dipole transition. We have used a pair of phase-locked chirped pulses of same frequency instead of a single chirped pulse to achieve phase control over the population transfer and thus creating coherent population distribution in hydrogen molecule. Simultaneous actions of the phase controlled interference and rapid adiabatic passages due to chirped pulses lead to the control in population transfer from the ground X(v = 0, j = 0) level to the C(v = 2, j = 1) level. We have extended this two-level system to a three-level 1 + 1 ladder system for population transfer from the X level to the J(v = 2, j = 2) level via the C intermediate level using two pairs of phase-locked laser chirped pulses and have achieved laudable control over the coherent population distribution.

Journal of Modern Optics•Jan 30, 2018•4 citations

Population transfer and coherence in the adiabatic limit by counterintuitive and intuitive pulse sequences

Zhou Yan-Wei, Ye Cun-Yun

Two approaches of achieving population transfer and coherence are investigated for the three-level Λ system in the adiabatic limit. The effects of the laser pulse sequence on the population transfer efficiency and coherence are studied. Coherent control of quantum state and population is studied by numerical simulation based on self-consistent set of density matrix equations. It can be seen that the counterintuitive pulse sequence is more efficient in population transfer and coherence than the intuitive one.

Chinese Physics•Jan 27, 2005•2 citations
Abstract The population transfer controlled by fundamental, 2nd-harmonic and 3rd-harmonic pulses is investigated by using the time-dependent quantum wave packet method. By varying the phase ϕ 1 of the fundamental pulse, it can be coherent with the 2nd-harmonic and 3rd-harmonic pulses. Compared with two harmonic pulses, the phase ϕ 1 in three harmonic pulses is more efficient in controlling population transfer. Molecular orientation can be controlled by the phases of the three pulses. The value of molecular orientation mainly depends on the phase coherence between the fundamental and 2nd-harmonic pulses.
The extended “ladder” transition controlled by two harmonic pulses is investigated by using a time-dependent quantum wave packet method. The molecular population transfers from the state|0, 0> angle to the states|5, 0> angle and|5, 2> angle induced by the fundamental and second-harmonic pulses, and to the states|5, 3> angle and |6, 2> angle induced by the fundamental and third-harmonic pulses. The calculated results show that the two harmonic pulses can induce a nearly 100% of population to transfer to the target state. The relative phase of two pulses can affect the population distribution. The variation of population has a period of π for the fundamental and second-harmonic pulses, and a period of 2π for the fundamental and third-harmonic pulses.
The processes of population transfer in the ground electronic state of HCl molecule through the three transition schemes are investigated by numerically solving the time-dependent Schrödinger equation. Two harmonic pulses are employed to induce population transfer and the relative phase of the two pulses can control the final population distributions. In the ladder transition scheme, the variation range of the target population with the relative phase is nearly 100% which is larger than that in the multi-photon transition scheme. It is more efficient for the mixed transition scheme to control population transfer between the initial and target states by using the relative phase. Comparing with the multi-photon and ladder schemes, the transition probability of the target population is more sensitive to the two pulse amplitudes in the mixed transition scheme.
A time-dependent quantum wave-packet method is employed to investigate the rovibrational dynamics of population transfer in the ground electronic state controlled by two-color ($\ensuremath{\omega}+2\ensuremath{\omega}$) pulses analogous to coherently control the processes of ionization and dissociation. The population can be transferred to three target states, $|4,1\ensuremath{\rangle},\phantom{\rule{0.16em}{0ex}}|0,1\ensuremath{\rangle}$, and $|4,0\ensuremath{\rangle}$, at the same time through the ladder $\ensuremath{\Lambda}$ and multiphoton transitions. With the variation of the relative phase between $\ensuremath{\omega}$ and $2\ensuremath{\omega}$ pulses, the population distributions show oscillation behavior with a period of $\ensuremath{\pi}$. The population variation with relative phase depends on the size of the electric field asymmetry. The probabilities transferred to different target states can be controlled by varying the pulse amplitudes.
A time-dependent approach to study phase control over molecular photoabsorption, provided by intense laser pulses, is elaborate. The method allows for the decay linewidth of molecular states and frequency bandwidth of the controlling laser field, and can be applied in weak and strong laser fields where the perturbation theory is invalid. It is shown that a frequency mismatch between the fundamental laser wave and its third harmonic can destroy control. For the example of the one-photon versus three-photon control a simple picture of interference from two monochromatic absorption pathways is not enough to explain phase control and one needs to consider a nonlinear temporal interference of multiquantum transitions. In the perturbation-theory limit an elegant generalization of the famous Shapiro-Hepburn-Brumer equation for the one-photon versus three-photon control is derived. Various numerical calculations illustrate the dependence of phase control on molecular linewidth, fundamental laser wavelength, pulse duration, and peak intensity. It is obtained, that the one-photon versus three-photon control is productive if the molecular state populations, individually produced by each laser wave, have beats of approximately the same frequency. The calculations demonstrate that an enough intense optical pulse can suppress molecular decay and may be used in order to keep stable the state population of a decaying molecule for a long time. The available experimental results for the one-photon versus three-photon control over simple and large polyatomic molecules are analyzed and recommendations for the experimental improvement of control are formulated.
A chirped laser pulse transfers population from one level to another level accessible by one photon dipole transition. We have used a pair of phase-locked chirped pulses of same frequency instead of a single chirped pulse to achieve phase control over the population transfer and thus creating coherent population distribution in hydrogen molecule. Simultaneous actions of the phase controlled interference and rapid adiabatic passages due to chirped pulses lead to the control in population transfer from the ground X(v = 0, j = 0) level to the C(v = 2, j = 1) level. We have extended this two-level system to a three-level 1 + 1 ladder system for population transfer from the X level to the J(v = 2, j = 2) level via the C intermediate level using two pairs of phase-locked laser chirped pulses and have achieved laudable control over the coherent population distribution.
Two approaches of achieving population transfer and coherence are investigated for the three-level Λ system in the adiabatic limit. The effects of the laser pulse sequence on the population transfer efficiency and coherence are studied. Coherent control of quantum state and population is studied by numerical simulation based on self-consistent set of density matrix equations. It can be seen that the counterintuitive pulse sequence is more efficient in population transfer and coherence than the intuitive one.