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:0907.1215

Analysis of adiabatic transfer in cavity QED

Joyee Ghosh, Rupamanjari Ghosh, Deepak Kumar

Published Jul 7, 2009• 1 citation
arXivHTMLPDF

Abstract

A three-level atom in a $Λ$ configuration trapped in an optical cavity forms a basic unit in a number of proposed protocols for quantum information processing. Through control with an appropriate laser, this system allows for efficient storage of cavity photons into long-lived atomic excitations, and their retrieval with high fidelity. This process presumes an adiabatic transfer through the `dark state', a coherent superposition of the two lower levels of the $Λ$ system, by a slow variation of the intensity of the control laser. We study the full quantum mechanics of this transfer process with a view to examine the nonadiabatic effects, as the control laser is varied in time. The nonadiabatic effects arise due to inevitable excitations of the system to states involving the highest level of the $Λ$ configuration, which is radiative. We formulate the problem in terms of the instantaneous eigenstates and solve it numerically, allowing for spontaneous decays from the excited level. We present detailed results for both storage and retrieval for a suitable range of variation rates and intensity of the control laser, and examine optimum conditions for the transfer process.

DOI
10.48550/arxiv.0907.1215

Related papers

Impact of non-adiabatic fields and dissipation on quantum storage and retrieval

Joyee Ghosh, Rupamanjari Ghosh, Deepak Kumar

In a Λ-type atomic system with electromagnetically-induced transparency, we probe the fidelity of the storage and retrieval of an electromagnetic signal, as the control laser field is varied with time. We study numerically the adiabatic transfer problem for an isolated atom, and show that for a weak signal, even the slowest variations of the control field take the system out of the dark state, which is a coherent superposition of the two lower levels of the Λ system. Following this, we incorporate the effect of dissipation on system dynamics by allowing for spontaneous decay of the system to the lower levels in a wavefunction approach. We conclude that dissipation definitely aids the retrieval process but not so much the storage. Further, for storing the signal, the control field should be switched off as slowly as possible, but while retrieving it, the faster we switch on the control field, the better the signal is retrieved. Also, for a given system there is an optimal control power for the best retrieval. Our results find partial support in the reported experimental observations.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Dec 29, 2008•0 citations

Coherent Manipulation of Multilevel Atoms for Quantum Information Processing

Juan D. Serna

In quantum information processing, quantum cavities play an important role by providing the mechanisms to transfer information between atom qubits and photon qubits, or to couple single atoms with the optical modes of the cavity field. We explore numerically the population transfer in an atom + cavity system by using the $π$-pulse and adiabatic passage methods. While the first method is very efficient transferring the atomic population for no radiative decay of the intermediate level, the second method shows very interesting nonadiabatic, resonance-like properties that can be used to achieve very large transfer efficiencies without needing very large Rabi frequencies or very long interaction times. We introduce a simple analytical model to explore the origin of these properties and describe "qualitatively" the power-law dependence of the failure probability on the product of the pulse amplitude and the interaction time. We also examine numerically the transfer of interatomic coherence in a two-atom + cavity system by using adiabatic methods. For some specific symmetry conditions, we show that the dynamics of the original system can be studied as the individual evolution of a symmetric and an antisymmetric system, interacting separately with the classical field and the cavity mode, but mutually exchanging the atomic coherence.

arXiv:1005.1119•May 7, 2010•0 citations

Active Quantum Memory Using Oscillating Dark States

Jun He, Yong-Sheng Zhang, Xiang-Fa Zhou +2 more

An active method for long time storage of quantum superposition state in atomic system using the Oscillating Dark States (ODS) is presented. Quantum state of a three-level $Λ$ configuration atomic system oscillates periodically between two ground levels, when two pairs of classical detuning laser fields driving the system into the ODS under evolving adiabatic conditions. When considering another uploading/unloading adiabatic conditions and applying the oscillation of the ODS to quantum state storage, surprisingly, we can obtain the greatly suppressed decoherence of the system and high fidelity of the retrieved state, even if decay factor of coherence term of the system density matrix $γ_{21}$$\cdot$ $t$$ \gg$1. The storage time is not limited by coherence decay time of the atomic system any longer, and can be thousands of times longer than that in those passive schemes without additional laser fields.

arXiv:0801.1941•Jan 13, 2008•0 citations

Raman adiabatic transfer of optical states in multilevel atoms

J. Appel, Karl-Peter Marzlin, Alexander I. Lvovsky

We analyze electromagnetically induced transparency and light storage in an ensemble of atoms with multiple excited levels (multi-$\ensuremath{\Lambda}$ configuration) which are coupled to one of the ground states by quantized signal fields and to the other one via classical control fields. We present a basis transformation of atomic and optical states which reduces the analysis of the system to that of electromagnetically induced transparency in a regular three-level configuration. We demonstrate the existence of dark state polaritons and propose a protocol to transfer quantum information from one optical mode to another by an adiabatic control of the control fields.

arXiv:quant-ph/0508151•Physical Review A•Jan 9, 2006•30 citations

Quantum processing by adiabatic transfer through a manifold of dark states

Santosh Kumar, Deepak Kumar

We consider a network whose nodes are electromagnetic cavities, each coupled to a single three-level atom. The nodes are connected by optical fibers. Each atom is addressed by a control laser, which along with the cavity field drives atomic transitions. The network can be in the form of chain or two- and three-dimensional arrays of $N$ cavities connected by ${N}_{B}$ fibers. Following the work on a two-cavity system by Pellizzari, we find that under certain conditions the system possesses two kinds of dark states. The first kind are $N$ states corresponding to atomic excitations at each node and these are our logical states for quantum processing. The second kind are ${N}_{B}$ degenerate dark states on pairs of sites connected by a fiber. By manipulating intensities and phases of control lasers on the cavities, one can pass adiabatically among these dark states due to their degeneracy. This network operates as an $N$-level quantum system in which one can generate computationally useful states by protocols of external controls. We obtain numerical results for small chains and lattices to demonstrate some quantum operations such as the transport of states across the array, generation of $W$ states, and Fourier-like states. We also discuss effects of dissipation and limitations of the model.

arXiv:1202.0408•Physical Review A•May 22, 2012•9 citations

Propagation of laser pulses and coherent population transfer in dissipative three-level systems: An adiabatic dressed-state picture

Michael Fleischhauer, Aaron S. Manka

The interaction of a pair of copropagating pulses with three-level \ensuremath{\Lambda}-type atoms is discussed in terms of time-dependent coupled and decoupled superpositions \ensuremath{\Vert}\ifmmode\pm\else\textpm\fi{}〉 of the lower levels. Due to the explicit time dependence of these states there is a nonadiabatic coupling between the ``bright'' state \ensuremath{\Vert}+〉 and the ``dark'' state \ensuremath{\Vert}-〉 in addition to the strong coupling between \ensuremath{\Vert}+〉 and the upper level \ensuremath{\Vert}a〉 . We show that under quasiadiabatic conditions and in the presence of decay from the upper level this coupling can be treated perturbatively and the Maxwell-Bloch equations can be solved analytically. With the help of such a perturbation approach, coherent population transfer and formstable laser pulse propagation are studied. \textcopyright{} 1996 The American Physical Society.

Physical Review A•Jul 1, 1996•134 citations
A three-level atom in a ΛΛΛ configuration trapped in an optical cavity forms a basic unit in a number of proposed protocols for quantum information processing. Through control with an appropriate laser, this system allows for efficient storage of cavity photons into long-lived atomic excitations, and their retrieval with high fidelity. This process presumes an adiabatic transfer through the `dark state', a coherent superposition of the two lower levels of the ΛΛΛ system, by a slow variation of the intensity of the control laser. We study the full quantum mechanics of this transfer process with a view to examine the nonadiabatic effects, as the control laser is varied in time. The nonadiabatic effects arise due to inevitable excitations of the system to states involving the highest level of the ΛΛΛ configuration, which is radiative. We formulate the problem in terms of the instantaneous eigenstates and solve it numerically, allowing for spontaneous decays from the excited level. We present detailed results for both storage and retrieval for a suitable range of variation rates and intensity of the control laser, and examine optimum conditions for the transfer process.
In a Λ-type atomic system with electromagnetically-induced transparency, we probe the fidelity of the storage and retrieval of an electromagnetic signal, as the control laser field is varied with time. We study numerically the adiabatic transfer problem for an isolated atom, and show that for a weak signal, even the slowest variations of the control field take the system out of the dark state, which is a coherent superposition of the two lower levels of the Λ system. Following this, we incorporate the effect of dissipation on system dynamics by allowing for spontaneous decay of the system to the lower levels in a wavefunction approach. We conclude that dissipation definitely aids the retrieval process but not so much the storage. Further, for storing the signal, the control field should be switched off as slowly as possible, but while retrieving it, the faster we switch on the control field, the better the signal is retrieved. Also, for a given system there is an optimal control power for the best retrieval. Our results find partial support in the reported experimental observations.
In quantum information processing, quantum cavities play an important role by providing the mechanisms to transfer information between atom qubits and photon qubits, or to couple single atoms with the optical modes of the cavity field. We explore numerically the population transfer in an atom + cavity system by using the πππ-pulse and adiabatic passage methods. While the first method is very efficient transferring the atomic population for no radiative decay of the intermediate level, the second method shows very interesting nonadiabatic, resonance-like properties that can be used to achieve very large transfer efficiencies without needing very large Rabi frequencies or very long interaction times. We introduce a simple analytical model to explore the origin of these properties and describe "qualitatively" the power-law dependence of the failure probability on the product of the pulse amplitude and the interaction time. We also examine numerically the transfer of interatomic coherence in a two-atom + cavity system by using adiabatic methods. For some specific symmetry conditions, we show that the dynamics of the original system can be studied as the individual evolution of a symmetric and an antisymmetric system, interacting separately with the classical field and the cavity mode, but mutually exchanging the atomic coherence.
An active method for long time storage of quantum superposition state in atomic system using the Oscillating Dark States (ODS) is presented. Quantum state of a three-level ΛΛΛ configuration atomic system oscillates periodically between two ground levels, when two pairs of classical detuning laser fields driving the system into the ODS under evolving adiabatic conditions. When considering another uploading/unloading adiabatic conditions and applying the oscillation of the ODS to quantum state storage, surprisingly, we can obtain the greatly suppressed decoherence of the system and high fidelity of the retrieved state, even if decay factor of coherence term of the system density matrix γ21γ_{21}γ21​⋅\cdot⋅ ttt$ \gg$1. The storage time is not limited by coherence decay time of the atomic system any longer, and can be thousands of times longer than that in those passive schemes without additional laser fields.
We analyze electromagnetically induced transparency and light storage in an ensemble of atoms with multiple excited levels (multi-$\ensuremath{\Lambda}$ configuration) which are coupled to one of the ground states by quantized signal fields and to the other one via classical control fields. We present a basis transformation of atomic and optical states which reduces the analysis of the system to that of electromagnetically induced transparency in a regular three-level configuration. We demonstrate the existence of dark state polaritons and propose a protocol to transfer quantum information from one optical mode to another by an adiabatic control of the control fields.
We consider a network whose nodes are electromagnetic cavities, each coupled to a single three-level atom. The nodes are connected by optical fibers. Each atom is addressed by a control laser, which along with the cavity field drives atomic transitions. The network can be in the form of chain or two- and three-dimensional arrays of NNN cavities connected by NB{N}_{B}NB​ fibers. Following the work on a two-cavity system by Pellizzari, we find that under certain conditions the system possesses two kinds of dark states. The first kind are NNN states corresponding to atomic excitations at each node and these are our logical states for quantum processing. The second kind are NB{N}_{B}NB​ degenerate dark states on pairs of sites connected by a fiber. By manipulating intensities and phases of control lasers on the cavities, one can pass adiabatically among these dark states due to their degeneracy. This network operates as an NNN-level quantum system in which one can generate computationally useful states by protocols of external controls. We obtain numerical results for small chains and lattices to demonstrate some quantum operations such as the transport of states across the array, generation of WWW states, and Fourier-like states. We also discuss effects of dissipation and limitations of the model.
The interaction of a pair of copropagating pulses with three-level \ensuremath{\Lambda}-type atoms is discussed in terms of time-dependent coupled and decoupled superpositions \ensuremath{\Vert}\ifmmode\pm\else\textpm\fi{}〉 of the lower levels. Due to the explicit time dependence of these states there is a nonadiabatic coupling between the ``bright'' state \ensuremath{\Vert}+〉 and the ``dark'' state \ensuremath{\Vert}-〉 in addition to the strong coupling between \ensuremath{\Vert}+〉 and the upper level \ensuremath{\Vert}a〉 . We show that under quasiadiabatic conditions and in the presence of decay from the upper level this coupling can be treated perturbatively and the Maxwell-Bloch equations can be solved analytically. With the help of such a perturbation approach, coherent population transfer and formstable laser pulse propagation are studied. \textcopyright{} 1996 The American Physical Society.