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:1309.6436 · Physical Review A

Dissipative preparation of phase- and number-squeezed states with ultracold atoms

Roland Cristopher F. Caballar, Sebastian Diehl, H. Mäkelä, Markus K. Oberthaler, Gentaro Watanabe A

Published Jan 24, 2014• 38 citations
arXivHTMLPDF

Abstract

We develop a dissipative quantum state preparation scheme for the creation of phase- and number-squeezed states. It utilizes ultracold atoms in a double-well configuration immersed in a background Bose-Einstein condensate, with the latter consisting of an atom species different from the atoms in the double well and acting as a dissipative quantum reservoir. We derive a master equation for this system starting from microscopic physics and show that squeezing develops on a time scale proportional to $1/N$, where $N$ is the number of particles in the double well. This scaling, caused by bosonic enhancement, allows us to make the time scale for the creation of squeezed states very short. The lifetime of squeezed states is limited by dephasing arising from the intrinsic structure of the setup. However, the dephasing can be avoided by stroboscopically switching the driving off and on. We show that this approach leads to robust stationary squeezed states. Finally, we provide the necessary ingredients for a potential experimental implementation by specifying a parameter regime for rubidium atoms that leads to squeezed states.

DOI
10.1103/physreva.89.013620

Related papers

Optimal control of number squeezing in trapped Bose-Einstein condensates

Julian Grond, G. von Winckel, Jörg Schmiedmayer +1 more

We theoretically analyze atom interferometry based on trapped ultracold atoms and employ optimal control theory in order to optimize number squeezing and condensate trapping. In our simulations, we consider a setup where the confinement potential is transformed from a single to a double well, which allows us to split the condensate. To avoid in the ensuing phase-accumulation stage of the interferometer dephasing due to the nonlinear atom-atom interactions, the atom-number fluctuations between the two wells should be sufficiently low. We show that low number fluctuations (high number squeezing) can be obtained by optimized splitting protocols. Two types of solutions are found: in the Josephson regime we find an oscillatory tunnel control and a parametric amplification of number squeezing, while in the Fock regime squeezing is obtained solely due to the nonlinear coupling, which is transformed to number squeezing by peaked tunnel pulses. We study splitting and squeezing within the frameworks of a generic two-mode model, which allows us to study the basic physical mechanisms and the multiconfigurational time-dependent Hartree for bosons method, which allows for a microscopic modeling of the splitting dynamics in realistic experiments. Both models give similar results, thus highlighting the general nature of these two solution schemes. We finally analyze our results in the context of atom interferometry.

arXiv:0908.1634•Physical Review A•Nov 24, 2009•71 citations

Creating Nonclassical States of Bose-Einstein Condensates by Dephasing Collisions

Nir Bar‐Gill, D. D. Bhaktavatsala Rao, Gershon Kurizki

We show, using an exactly solvable model, that nonlinear dynamics is induced in a double-well Bose-Einstein condensate (BEC) by collisions with a thermal reservoir. This dynamics can facilitate the creation of phase or number squeezing and, at longer times, the creation of macroscopic nonclassical superposition states. Enhancement of these effects is possible by loading the reservoir atoms into an optical lattice.

Physical Review Letters•Jul 1, 2011•36 citations

Dynamic generation of spin-squeezed states in bosonic Josephson junctions

Bruno Juliá-Díaz, Tilman Zibold, Markus K. Oberthaler +3 more

We analyze the formation of squeezed states in a condensate of ultracold bosonic atoms confined by a double-well potential. The emphasis is set on the dynamical formation of such states from initially coherent many-body quantum states. Two cases are described: the squeezing formation in the evolution of the system around the stable point, and in the short-time evolution in the vicinity of an unstable point. The latter is shown to produce highly squeezed states on very short times. On the basis of a semiclassical approximation to the Bose-Hubbard Hamiltonian, we are able to predict the amount of squeezing, its scaling with $N$, and the speed of coherent spin formation with simple analytical formulas which successfully describe the numerical Bose-Hubbard results. This method of producing highly squeezed spin states in systems of ultracold atoms is compared to other standard methods in the literature.

arXiv:1205.6756•Physical Review A•Aug 14, 2012•88 citations

Parametric-squeezing amplification of Bose-Einstein condensates

Georg Jäger, Tarik Berrada, Jörg Schmiedmayer +2 more

We theoretically investigate the creation of squeezed states of a Bose-Einstein condensate (BEC) trapped in a magnetic double-well potential. The number or phase squeezed states are created by modulating the tunnel coupling between the two wells periodically with twice the Josephson frequency, i.e., through parametric amplification. Simulations are performed with the multiconfigurational time-dependent Hartree method for bosons. We employ optimal control theory to bring the condensate to a complete halt at a final time, thus creating a highly squeezed state (squeezing factor of 0.12, ${\ensuremath{\xi}}_{S}^{2}=\ensuremath{-}18$ dB) suitable for atom interferometry.

arXiv:1511.03146•Physical Review A•Nov 30, 2015•11 citations

Giant-atom dephasing dynamics and entanglement generation in a squeezed vacuum reservoir

Xian‐Li Yin, Joseph H. W. Lee, Guofeng Zhang

The study of atomic behaviors in a squeezed vacuum reservoir plays an important role in exploring quantum effect and quantum physics. We here propose a scheme to manipulate the dynamics of giant atoms coupled to a one-dimensional waveguide driven by a broadband squeezed field, which acts as a squeezed vacuum reservoir. By tuning the propagating phase of photons, the center-of-mass phase of the giant atom, and the squeezing parameter, both the dephasing dynamics and entanglement dynamics of giant atoms can be effectively controlled. In the single-giant-atom case, we obtain the expressions of the dephasing rates based on the Bloch equations derived from the quantum master equation of the giant atom. Adjusting these two phases enables the dephasing rates to be enhanced, suppressed, or reduced to zero, thereby changing the dephasing dynamics. For the two-giant-atom system, we find that the atomic individual and collective squeezing depend on these two phases simultaneously. The steady-state giant-atom population and entanglement are obtained by working in the collective state representation for the two atoms. Different from small atoms, the steady-state population and entanglement depend on not only the center-mass-of phase, but also the propagating phase. In addition, we identify the condition for achieving larger steady-state entanglement via analyzing the system parameters. This work will facilitate the study of light-matter interaction based on giant-atom waveguide QED systems driven by a squeezed vacuum reservoir and has potential applications in quantum information processing.

Physical Review A•Mar 13, 2025•12 citations

Global phase space of coherence and entanglement in a double-well Bose-Einstein condensate

Holger Hennig, Dirk Witthaut, David K Campbell

Ultracold atoms provide an ideal system for the realization of quantum technologies but also for the study of fundamental physical questions such as the emergence of decoherence and classicality in quantum many-body systems. Here, we study the global structure of the quantum dynamics of bosonic atoms in a double-well trap based upon the Bose-Hubbard Hamiltonian and analyze the conditions for the generation of many-particle entanglement and spin squeezing which have important applications in quantum metrology. We show how the quantum dynamics is determined by the phase-space structure of the associated mean-field system and where true quantum features arise beyond this ``classical'' approximation.

arXiv:1206.0284•Physical Review A•Nov 12, 2012•21 citations
We develop a dissipative quantum state preparation scheme for the creation of phase- and number-squeezed states. It utilizes ultracold atoms in a double-well configuration immersed in a background Bose-Einstein condensate, with the latter consisting of an atom species different from the atoms in the double well and acting as a dissipative quantum reservoir. We derive a master equation for this system starting from microscopic physics and show that squeezing develops on a time scale proportional to 1/N1/N1/N, where NNN is the number of particles in the double well. This scaling, caused by bosonic enhancement, allows us to make the time scale for the creation of squeezed states very short. The lifetime of squeezed states is limited by dephasing arising from the intrinsic structure of the setup. However, the dephasing can be avoided by stroboscopically switching the driving off and on. We show that this approach leads to robust stationary squeezed states. Finally, we provide the necessary ingredients for a potential experimental implementation by specifying a parameter regime for rubidium atoms that leads to squeezed states.
We theoretically analyze atom interferometry based on trapped ultracold atoms and employ optimal control theory in order to optimize number squeezing and condensate trapping. In our simulations, we consider a setup where the confinement potential is transformed from a single to a double well, which allows us to split the condensate. To avoid in the ensuing phase-accumulation stage of the interferometer dephasing due to the nonlinear atom-atom interactions, the atom-number fluctuations between the two wells should be sufficiently low. We show that low number fluctuations (high number squeezing) can be obtained by optimized splitting protocols. Two types of solutions are found: in the Josephson regime we find an oscillatory tunnel control and a parametric amplification of number squeezing, while in the Fock regime squeezing is obtained solely due to the nonlinear coupling, which is transformed to number squeezing by peaked tunnel pulses. We study splitting and squeezing within the frameworks of a generic two-mode model, which allows us to study the basic physical mechanisms and the multiconfigurational time-dependent Hartree for bosons method, which allows for a microscopic modeling of the splitting dynamics in realistic experiments. Both models give similar results, thus highlighting the general nature of these two solution schemes. We finally analyze our results in the context of atom interferometry.
We analyze the formation of squeezed states in a condensate of ultracold bosonic atoms confined by a double-well potential. The emphasis is set on the dynamical formation of such states from initially coherent many-body quantum states. Two cases are described: the squeezing formation in the evolution of the system around the stable point, and in the short-time evolution in the vicinity of an unstable point. The latter is shown to produce highly squeezed states on very short times. On the basis of a semiclassical approximation to the Bose-Hubbard Hamiltonian, we are able to predict the amount of squeezing, its scaling with NNN, and the speed of coherent spin formation with simple analytical formulas which successfully describe the numerical Bose-Hubbard results. This method of producing highly squeezed spin states in systems of ultracold atoms is compared to other standard methods in the literature.
We theoretically investigate the creation of squeezed states of a Bose-Einstein condensate (BEC) trapped in a magnetic double-well potential. The number or phase squeezed states are created by modulating the tunnel coupling between the two wells periodically with twice the Josephson frequency, i.e., through parametric amplification. Simulations are performed with the multiconfigurational time-dependent Hartree method for bosons. We employ optimal control theory to bring the condensate to a complete halt at a final time, thus creating a highly squeezed state (squeezing factor of 0.12, ${\ensuremath{\xi}}_{S}^{2}=\ensuremath{-}18$ dB) suitable for atom interferometry.
The study of atomic behaviors in a squeezed vacuum reservoir plays an important role in exploring quantum effect and quantum physics. We here propose a scheme to manipulate the dynamics of giant atoms coupled to a one-dimensional waveguide driven by a broadband squeezed field, which acts as a squeezed vacuum reservoir. By tuning the propagating phase of photons, the center-of-mass phase of the giant atom, and the squeezing parameter, both the dephasing dynamics and entanglement dynamics of giant atoms can be effectively controlled. In the single-giant-atom case, we obtain the expressions of the dephasing rates based on the Bloch equations derived from the quantum master equation of the giant atom. Adjusting these two phases enables the dephasing rates to be enhanced, suppressed, or reduced to zero, thereby changing the dephasing dynamics. For the two-giant-atom system, we find that the atomic individual and collective squeezing depend on these two phases simultaneously. The steady-state giant-atom population and entanglement are obtained by working in the collective state representation for the two atoms. Different from small atoms, the steady-state population and entanglement depend on not only the center-mass-of phase, but also the propagating phase. In addition, we identify the condition for achieving larger steady-state entanglement via analyzing the system parameters. This work will facilitate the study of light-matter interaction based on giant-atom waveguide QED systems driven by a squeezed vacuum reservoir and has potential applications in quantum information processing.
Ultracold atoms provide an ideal system for the realization of quantum technologies but also for the study of fundamental physical questions such as the emergence of decoherence and classicality in quantum many-body systems. Here, we study the global structure of the quantum dynamics of bosonic atoms in a double-well trap based upon the Bose-Hubbard Hamiltonian and analyze the conditions for the generation of many-particle entanglement and spin squeezing which have important applications in quantum metrology. We show how the quantum dynamics is determined by the phase-space structure of the associated mean-field system and where true quantum features arise beyond this ``classical'' approximation.