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

Physical Review A

Quantum-field coherent control: Preparation of broken-symmetry entangled states

Petr Král, Ioannis Thanopulos, Moshe Shapiro

Published Aug 30, 2005• 22 citations
Publisher

Abstract

We show that entangled radiation-matter states with broken symmetries can be prepared by using nonclassical light in the coherent control techniques. We demonstrate the method by realizing the entanglement in degenerate continuum electronic momentum states of opposite directionality and discrete states of opposite handedness in chiral molecules. When the material system is excited simultaneously by classical light and quantum light in a state with several semiclassical phases, the interference conditions guide the system to such entangled radiation-matter states.

DOI
10.1103/physreva.72.020303

Related papers

Macroscopically entangled light fields: A quantum laser

Byoung Seung HAM

A novel method of macroscopically entangled light-pair generation is presented for a quantum laser using randomness-based deterministic phase control of coherent light in a Mach-Zehnder interferometer (MZI). Unlike the particle nature-based quantum correlation in conventional quantum mechanics, the wave nature of photons is applied for collective phase control of coherent fields, resulting in a deterministically controllable nonclassical phenomenon. For the proof of principle, the entanglement between output light fields from an MZI is examined using the Hong-Ou-Mandel-type anticorrelation technique, where the anticorrelation is a direct evidence of the nonclassical features in an interferometric scheme. For the generation of random phase bases between two bipartite input coherent fields, a deterministic control of opposite frequency shifts results in phase sensitive anticorrelation, which is a macroscopic quantum feature.

arXiv:2102.04659•Feb 9, 2021•0 citations

Generating and controlling chains of entangled atoms by coherent control techniques

Moshe Shapiro

A practical way of writing long sequences of entangled atomic qubits using coherent control with classical light sources is proposed. The method utilizes one-photon vs two-photon interference as a means of controlling the directionality of the motion of valence electrons during molecular dissociation processes. We show that, by dissociating in an optical lattice a one-dimensional array of ultracold diatomic molecules (e.g., ${\mathrm{Na}}_{2}\ensuremath{\rightarrow}\mathrm{Na}+{\mathrm{Na}}^{*}$), using a combination of photoabsorption of two mutually perpendicularly polarized beams at center frequency $\ensuremath{\omega}$ and a coherent Raman transition at frequencies ${\ensuremath{\omega}}_{1}$ and ${\ensuremath{\omega}}_{2}={\ensuremath{\omega}}_{1}\ensuremath{-}\ensuremath{\omega}$, one can craft entangled states composed of arbitrary superpositions of sequences of atomic states, such as $|f\ensuremath{\rangle}|f\ensuremath{\rangle}|b\ensuremath{\rangle}+\ensuremath{\cdots}+|b\ensuremath{\rangle}|b\ensuremath{\rangle}|f\ensuremath{\rangle}+\ensuremath{\cdots},$ where $|f\ensuremath{\rangle}$ designates a dissociation process in which the ground-state Na atom goes in the forwarddirection and the excited-state Na${}^{*}$ goes in the backward direction, while $|b\ensuremath{\rangle}$ designates the reverse process, namely, Na going in the backward direction and Na${}^{*}$ going in the forward direction. The method, which on the basis of past work is expected to be robust against decoherence, would enable the encoding of very long sequences of entangled qubits.

Physical Review A•Nov 28, 2011•6 citations

Indistinguishability and interference in the coherent control of atomic and molecular processes

Jiangbin Gong, Paul W. Brumer

The subtle and fundamental issue of indistinguishability and interference between independent pathways to the same target state is examined in the context of coherent control of atomic and molecular processes, with emphasis placed on possible "which-way" information due to quantum entanglement established in the quantum dynamics. Because quantum interference between independent pathways to the same target state occurs only when the independent pathways are indistinguishable, it is first shown that creating useful coherence between nondegenerate states of a molecule for subsequent quantum interference manipulation cannot be achieved by collisions between atoms or molecules that are prepared in momentum and energy eigenstates. Coherence can, however, be transferred from light fields to atoms or molecules. Using a particular coherent control scenario, it is shown that this coherence transfer and the subsequent coherent phase control can be readily realized by the most classical states of light, i.e., coherent states of light. It is further demonstrated that quantum states of light may suppress the extent of phase-sensitive coherent control by leaking out some which-way information while "incoherent interference control" scenarios proposed in the literature have automatically ensured the indistinguishability of multiple excitation pathways. The possibility of quantum coherence in photodissociation product states is also understood in terms of the disentanglement between photodissociation fragments. Results offer deeper insights into quantum coherence generation in atomic and molecular processes.

arXiv:1002.1438•The Journal of Chemical Physics•Feb 5, 2010•11 citations

Macroscopically entangled light fields

Byoung Seung HAM

A novel method of macroscopically entangled light-pair generation is presented for a quantum laser using randomness-based deterministic phase control of coherent light in a coupled Mach-Zehnder interferometer (MZI). Unlike the particle nature-based quantum correlation in conventional quantum mechanics, the wave nature of photons is applied for collective phase control of coherent fields, resulting in a deterministically controllable nonclassical phenomenon. For the proof of principle, the entanglement between output light fields from a coupled MZI is examined using the Hong-Ou-Mandel-type anticorrelation technique, where the anticorrelation is a direct evidence of the nonclassical features in an interferometric scheme. For the generation of random phase bases between two bipartite input coherent fields, a deterministic control of opposite frequency shifts results in phase sensitive anticorrelation, which is a macroscopic quantum feature.

Scientific Reports•May 31, 2021•5 citations

Coherent control of molecular dynamics

Moshe Shapiro, Paul W. Brumer

We review the principles and some recent advances in the theory of coherent control of molecular processes and discuss some of its experimental realizations. Amongst the topics discussed are: bichromatic and pump-dump control; the interference between N-photons and M-photon processes; the optical conversion of a mixture of left- and right-handed chiral molecules into an ensemble containing molecules of the handedness of choice; control of collisional processes; control over chaotic dynamics; effects of decoherence; the solution of the non-degenerate quantum control problem; and control over spontaneous emission and other decay processes.

Reports on Progress in Physics•May 13, 2003•213 citations

Entanglement and non-classical states of light in a strong-laser driven solid-state system

Javier Rivera-Dean, Philipp Stammer, Andrew Maxwell +6 more

The development of sources delivering non-classical states of light is one of the main needs for applications of optical quantum information science. Here, we demonstrate the generation of non-classical states of light using strong-laser fields driving a solid-state system, by using the process of high-order harmonic generation, where an electron tunnels out of the parent site and, later on, recombines on it emitting high-order harmonic radiation, at the expense of affecting the driving laser field. Since in solid-state systems the recombination of the electron can be delocalized along the material, the final state of the electron determines how the electromagnetic field gets affected because of the laser-matter interaction, leading to the generation of entanglement between the electron and the field. These features can be enhanced by applying conditioning operations, i.e., quantum operations based on the measurement of high-harmonic radiation. We study non-classical features present in the final quantum optical state, and characterize the amount of entanglement between the light and the electrons in the solid. The work sets the foundation for the development of compact solid-state-based non-classical light sources using strong-field physics.

arXiv:2211.00033•Oct 31, 2022•5 citations
We show that entangled radiation-matter states with broken symmetries can be prepared by using nonclassical light in the coherent control techniques. We demonstrate the method by realizing the entanglement in degenerate continuum electronic momentum states of opposite directionality and discrete states of opposite handedness in chiral molecules. When the material system is excited simultaneously by classical light and quantum light in a state with several semiclassical phases, the interference conditions guide the system to such entangled radiation-matter states.
A novel method of macroscopically entangled light-pair generation is presented for a quantum laser using randomness-based deterministic phase control of coherent light in a Mach-Zehnder interferometer (MZI). Unlike the particle nature-based quantum correlation in conventional quantum mechanics, the wave nature of photons is applied for collective phase control of coherent fields, resulting in a deterministically controllable nonclassical phenomenon. For the proof of principle, the entanglement between output light fields from an MZI is examined using the Hong-Ou-Mandel-type anticorrelation technique, where the anticorrelation is a direct evidence of the nonclassical features in an interferometric scheme. For the generation of random phase bases between two bipartite input coherent fields, a deterministic control of opposite frequency shifts results in phase sensitive anticorrelation, which is a macroscopic quantum feature.
A practical way of writing long sequences of entangled atomic qubits using coherent control with classical light sources is proposed. The method utilizes one-photon vs two-photon interference as a means of controlling the directionality of the motion of valence electrons during molecular dissociation processes. We show that, by dissociating in an optical lattice a one-dimensional array of ultracold diatomic molecules (e.g., ${\mathrm{Na}}_{2}\ensuremath{\rightarrow}\mathrm{Na}+{\mathrm{Na}}^{*}$), using a combination of photoabsorption of two mutually perpendicularly polarized beams at center frequency $\ensuremath{\omega}$ and a coherent Raman transition at frequencies ${\ensuremath{\omega}}_{1}$ and ${\ensuremath{\omega}}_{2}={\ensuremath{\omega}}_{1}\ensuremath{-}\ensuremath{\omega}$, one can craft entangled states composed of arbitrary superpositions of sequences of atomic states, such as $|f\ensuremath{\rangle}|f\ensuremath{\rangle}|b\ensuremath{\rangle}+\ensuremath{\cdots}+|b\ensuremath{\rangle}|b\ensuremath{\rangle}|f\ensuremath{\rangle}+\ensuremath{\cdots},$ where $|f\ensuremath{\rangle}$ designates a dissociation process in which the ground-state Na atom goes in the forwarddirection and the excited-state Na∗{}^{*}∗ goes in the backward direction, while $|b\ensuremath{\rangle}$ designates the reverse process, namely, Na going in the backward direction and Na∗{}^{*}∗ going in the forward direction. The method, which on the basis of past work is expected to be robust against decoherence, would enable the encoding of very long sequences of entangled qubits.
The subtle and fundamental issue of indistinguishability and interference between independent pathways to the same target state is examined in the context of coherent control of atomic and molecular processes, with emphasis placed on possible "which-way" information due to quantum entanglement established in the quantum dynamics. Because quantum interference between independent pathways to the same target state occurs only when the independent pathways are indistinguishable, it is first shown that creating useful coherence between nondegenerate states of a molecule for subsequent quantum interference manipulation cannot be achieved by collisions between atoms or molecules that are prepared in momentum and energy eigenstates. Coherence can, however, be transferred from light fields to atoms or molecules. Using a particular coherent control scenario, it is shown that this coherence transfer and the subsequent coherent phase control can be readily realized by the most classical states of light, i.e., coherent states of light. It is further demonstrated that quantum states of light may suppress the extent of phase-sensitive coherent control by leaking out some which-way information while "incoherent interference control" scenarios proposed in the literature have automatically ensured the indistinguishability of multiple excitation pathways. The possibility of quantum coherence in photodissociation product states is also understood in terms of the disentanglement between photodissociation fragments. Results offer deeper insights into quantum coherence generation in atomic and molecular processes.
A novel method of macroscopically entangled light-pair generation is presented for a quantum laser using randomness-based deterministic phase control of coherent light in a coupled Mach-Zehnder interferometer (MZI). Unlike the particle nature-based quantum correlation in conventional quantum mechanics, the wave nature of photons is applied for collective phase control of coherent fields, resulting in a deterministically controllable nonclassical phenomenon. For the proof of principle, the entanglement between output light fields from a coupled MZI is examined using the Hong-Ou-Mandel-type anticorrelation technique, where the anticorrelation is a direct evidence of the nonclassical features in an interferometric scheme. For the generation of random phase bases between two bipartite input coherent fields, a deterministic control of opposite frequency shifts results in phase sensitive anticorrelation, which is a macroscopic quantum feature.
We review the principles and some recent advances in the theory of coherent control of molecular processes and discuss some of its experimental realizations. Amongst the topics discussed are: bichromatic and pump-dump control; the interference between N-photons and M-photon processes; the optical conversion of a mixture of left- and right-handed chiral molecules into an ensemble containing molecules of the handedness of choice; control of collisional processes; control over chaotic dynamics; effects of decoherence; the solution of the non-degenerate quantum control problem; and control over spontaneous emission and other decay processes.
The development of sources delivering non-classical states of light is one of the main needs for applications of optical quantum information science. Here, we demonstrate the generation of non-classical states of light using strong-laser fields driving a solid-state system, by using the process of high-order harmonic generation, where an electron tunnels out of the parent site and, later on, recombines on it emitting high-order harmonic radiation, at the expense of affecting the driving laser field. Since in solid-state systems the recombination of the electron can be delocalized along the material, the final state of the electron determines how the electromagnetic field gets affected because of the laser-matter interaction, leading to the generation of entanglement between the electron and the field. These features can be enhanced by applying conditioning operations, i.e., quantum operations based on the measurement of high-harmonic radiation. We study non-classical features present in the final quantum optical state, and characterize the amount of entanglement between the light and the electrons in the solid. The work sets the foundation for the development of compact solid-state-based non-classical light sources using strong-field physics.