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

arXiv:2511.05161 · Physical Review A

Coherent control of quantum states by quadratically chirped short laser pulses

G. P. Djotyan, A. A. Avetisyan, A. P. Djotyan

quant-phphysics.opticsSubmitted Nov 7, 2025• Announced Nov 10, 2025• 1 citation
arXivHTMLPDF

Abstract

We present a novel scheme for coherent manipulation of populations and robust creation of arbitrary coherent superposition of metastable states of a quantum system with lambda configuration of operating energy levels using laser pulses with a quadratically chirped carrier frequency. The case of a single broadband laser pulse is considered, when the frequency spectrum of the pulse exceeds the frequency distance between the metastable energy levels of the system. The results of the dressed state analysis and numerical simulation are presented, demonstrating reliable and robust creation of an arbitrary coherent superposition of metastable states by changing the parameters of laser pulses.

Comments
19 pages, 11 figures

Related papers

Reversible Generation of Coherence between Metastable Quantum States Using Laser Pulses with Quadratic Frequency Chirp

Gagik P. Djotyan, A. A. Avetisyan, A. P. Djotyan

Abstract In this paper, we show that the scheme we previously developed for creating a controlled coherent superposition of metastable states in a quantum system, under certain conditions, allows the reversible generation of arbitrary coherence between these states. This scheme utilizes laser pulses with a quadratic frequency chirp (QFC). While the first QFC laser pulse generates the required superposition of metastable states, a subsequent QFC laser pulse with the same parameters as the previous one, but with the opposite direction of frequency chirp, returns the quantum system to its original state, allowing another required coherence value to be formed by applying the next QFC pulse with the appropriate parameters. The case of a single “broadband” QFC laser pulse is considered, when the frequency spectrum of the pulse (without chirp) exceeds the frequency distance between the metastable energy levels of the system.

Journal of Contemporary Physics (Armenian Academy of Sciences)•Mar 1, 2026•0 citations

Creation of a coherent superposition of quantum states by a single frequency-chirped short laser pulse

Gagik P. Djotyan, Jozsef S. Bakos, G. Demeter +3 more

Traditional schemes for coherent population transfer or generation of coherent superposition states in multilevel atoms or molecules usually utilize two or more laser beams with radiation bandwidth smaller than the frequency interval between the working levels. We show the possibility of creation of the coherent superposition of three metastable states of a four-level atom with tripodlike level structure using a single short frequency-chirped laser pulse. The bandwidth of the pulse envelope (without chirp) must be comparable to or exceed the frequency distance between the two metastable levels. No appreciable excitation of the atom takes place during the creation of the coherent superposition state, thus diminishing significantly the effect of decoherence due to the spontaneous decay of the excited state. The proposed method of creation of superposition states is robust against variations in the laser pulse parameters. Since this method does not require maintaining steady resonance with the atomic transitions (owing to the frequency chirp of the laser pulse), it is effective both in homogeneously and inhomogeneously broadened media.

Journal of the Optical Society of America B•Jan 14, 2008•19 citations

Population transfer and generation of arbitrary superpositions of quantum states in a four-level system using a single-chirped laser pulse

Zhenhua Zhang, Xihua Yang, Xiaona Yan

We propose a scheme for coherent control of population transfer and arbitrary superpositions of quantum states by a single-chirped laser pulse in a Λ-type excited-doublet four-level system. It is shown that selective, efficient, and robust population transfer from the initial state to the target states (excited or ground) can be achieved via chirped adiabatic passage when the pulse bandwidth is smaller than about 1/10 of the energy separations between the excited-doublet levels and between the ground states. Moreover, arbitrary coherent superpositions between the excited-doublet states, or between the higher ground state and either of the excited-doublet states, can be created by appropriately tuning the chirp rate and detuning the laser field. The proposed flexible method of coherent control of population transfer and arbitrary superpositions between the initially unpopulated states requires only a single pulse, and is robust against variations in the laser parameters, which has potential applications in quantum information processing.

Journal of the Optical Society of America B•Mar 22, 2013•17 citations

Selective population transfer and creation of an arbitrary superposition between quantum states in a Λ-type four-level system by a single linearly chirped pulse

Zhenhua Zhang, Tian Jin, Juan Du

Abstract We present a simple and robust way to execute selective population transfer and creation of an arbitrary superposition between quantum states in a Λ-type four-level system with doublet ground states driven by a single linearly chirped pulse. It is demonstrated that the population in the initial state can be completely and flexibly transferred to either of the target states by manipulating the chirp rate and detuning of the laser pulse. Besides, the formation of an arbitrary superposition between the initial state and either of the target states through properly changing the chirp rate and detuning is also exhibited. The results of this method can be useful for selective quantum coherent control in systems with multiple target states.

Laser Physics Letters•Mar 21, 2016•5 citations

Coherent control of atomic quantum states by single frequency-chirped laser pulses

Gagik P. Djotyan, Jozsef S. Bakos, Zs. Sörlei +1 more

We present a scheme of population transfer between two metastable (ground) states of the $\ensuremath{\Lambda}$ atom without considerable excitation of the atom using single frequency-chirped laser pulses. The physics of the process is generation of the ``trapped'' superposition of the ground states by the laser pulse at sufficiently high laser peak intensity. The main conditions for realization of this regime are the following: The width of the transform-limited laser pulse envelope frequency spectrum (without chirp) must be smaller and the peak Rabi frequency of the pulse must be larger than the frequency interval between the two ground states of the $\ensuremath{\Lambda}$ atom. During the frequency chirp, the laser pulse must first come into resonance with the transition from the initially occupied ground state to the excited state and after that with the transition between the excited and second initially empty ground states. In the case when the envelope frequency spectrum width (without chirp) of the pulse exceeds the frequency interval between the two ground states, we show a possibility of controllable generation of superposition of the ground states with a controllable excitation of the $\ensuremath{\Lambda}$ atom.

Physical Review A•Dec 10, 2004•50 citations

Creation of an arbitrary coherent superposition state with chirped delayed pulses

Li Deng, Niu Yue-Ping, Xiang yang +2 more

We demonstrate numerically that in a three-level Λ-type atomic system, by using two laser pulses, it is able to create arbitrary coherent superposition of the two lower levels via varying the linear chirp rate of the pump pulse in the case of two-photon detunings. The underlying physics of the phenomenon is given by analysing the Hamiltonian of the system on the basis of dressed states. We find that the phenomenon is due to the existence of two anticrossings of the closely spaced dressed states.

Journal of Physics B Atomic Molecular and Optical Physics•Jan 19, 2010•9 citations
We present a novel scheme for coherent manipulation of populations and robust creation of arbitrary coherent superposition of metastable states of a quantum system with lambda configuration of operating energy levels using laser pulses with a quadratically chirped carrier frequency. The case of a single broadband laser pulse is considered, when the frequency spectrum of the pulse exceeds the frequency distance between the metastable energy levels of the system. The results of the dressed state analysis and numerical simulation are presented, demonstrating reliable and robust creation of an arbitrary coherent superposition of metastable states by changing the parameters of laser pulses.
Abstract In this paper, we show that the scheme we previously developed for creating a controlled coherent superposition of metastable states in a quantum system, under certain conditions, allows the reversible generation of arbitrary coherence between these states. This scheme utilizes laser pulses with a quadratic frequency chirp (QFC). While the first QFC laser pulse generates the required superposition of metastable states, a subsequent QFC laser pulse with the same parameters as the previous one, but with the opposite direction of frequency chirp, returns the quantum system to its original state, allowing another required coherence value to be formed by applying the next QFC pulse with the appropriate parameters. The case of a single “broadband” QFC laser pulse is considered, when the frequency spectrum of the pulse (without chirp) exceeds the frequency distance between the metastable energy levels of the system.
Traditional schemes for coherent population transfer or generation of coherent superposition states in multilevel atoms or molecules usually utilize two or more laser beams with radiation bandwidth smaller than the frequency interval between the working levels. We show the possibility of creation of the coherent superposition of three metastable states of a four-level atom with tripodlike level structure using a single short frequency-chirped laser pulse. The bandwidth of the pulse envelope (without chirp) must be comparable to or exceed the frequency distance between the two metastable levels. No appreciable excitation of the atom takes place during the creation of the coherent superposition state, thus diminishing significantly the effect of decoherence due to the spontaneous decay of the excited state. The proposed method of creation of superposition states is robust against variations in the laser pulse parameters. Since this method does not require maintaining steady resonance with the atomic transitions (owing to the frequency chirp of the laser pulse), it is effective both in homogeneously and inhomogeneously broadened media.
We propose a scheme for coherent control of population transfer and arbitrary superpositions of quantum states by a single-chirped laser pulse in a Λ-type excited-doublet four-level system. It is shown that selective, efficient, and robust population transfer from the initial state to the target states (excited or ground) can be achieved via chirped adiabatic passage when the pulse bandwidth is smaller than about 1/10 of the energy separations between the excited-doublet levels and between the ground states. Moreover, arbitrary coherent superpositions between the excited-doublet states, or between the higher ground state and either of the excited-doublet states, can be created by appropriately tuning the chirp rate and detuning the laser field. The proposed flexible method of coherent control of population transfer and arbitrary superpositions between the initially unpopulated states requires only a single pulse, and is robust against variations in the laser parameters, which has potential applications in quantum information processing.
Abstract We present a simple and robust way to execute selective population transfer and creation of an arbitrary superposition between quantum states in a Λ-type four-level system with doublet ground states driven by a single linearly chirped pulse. It is demonstrated that the population in the initial state can be completely and flexibly transferred to either of the target states by manipulating the chirp rate and detuning of the laser pulse. Besides, the formation of an arbitrary superposition between the initial state and either of the target states through properly changing the chirp rate and detuning is also exhibited. The results of this method can be useful for selective quantum coherent control in systems with multiple target states.
We present a scheme of population transfer between two metastable (ground) states of the $\ensuremath{\Lambda}$ atom without considerable excitation of the atom using single frequency-chirped laser pulses. The physics of the process is generation of the ``trapped'' superposition of the ground states by the laser pulse at sufficiently high laser peak intensity. The main conditions for realization of this regime are the following: The width of the transform-limited laser pulse envelope frequency spectrum (without chirp) must be smaller and the peak Rabi frequency of the pulse must be larger than the frequency interval between the two ground states of the $\ensuremath{\Lambda}$ atom. During the frequency chirp, the laser pulse must first come into resonance with the transition from the initially occupied ground state to the excited state and after that with the transition between the excited and second initially empty ground states. In the case when the envelope frequency spectrum width (without chirp) of the pulse exceeds the frequency interval between the two ground states, we show a possibility of controllable generation of superposition of the ground states with a controllable excitation of the $\ensuremath{\Lambda}$ atom.
We demonstrate numerically that in a three-level Λ-type atomic system, by using two laser pulses, it is able to create arbitrary coherent superposition of the two lower levels via varying the linear chirp rate of the pump pulse in the case of two-photon detunings. The underlying physics of the phenomenon is given by analysing the Hamiltonian of the system on the basis of dressed states. We find that the phenomenon is due to the existence of two anticrossings of the closely spaced dressed states.