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:quant-ph/0209023 · Physical Review A

Atomic spin squeezing in a Λ system

Aurélien Dantan, M. Pinard, Vincent Josse, N. Nayak, P. R. Berman

Published Apr 22, 2003• 37 citations
arXivHTMLPDF

Abstract

Using a quantum theory for an ensemble of three-level atoms $(\ensuremath{\Lambda})$ placed in an optical cavity and driven by electromagnetic fields, we show that the long-lived spin associated with the ground-state sublevels can be squeezed. Two kinds of squeezing are obtained: self-spin squeezing, when the input fields are coherent states and the atomic ensemble exhibits a large nonlinearity; squeezing transfer approaching 100%, when one of the incoming fields is squeezed.

DOI
10.1103/physreva.67.045801

Related papers

Atomic spin squeezing in a Lambda system

Aurélien Dantan, M. Pinard, Vincent Josse +2 more

Using a quantum theory for an ensemble of three-level atoms (lambda) placed in an optical cavity abd driven by electromagnetic fields, we show that the long-lived spin associated with the ground state sublevels can be squeezed. Two kinds of squeezing are obtained: self-spin squeezing, when the input fields are coherent states and the atomic ensemble exhibit a large non-linearity; squeezing transfer, when one of the incoming fields is squeezed.

•Jan 1, 2003•1 citation

Spin squeezing in two-level systems

L. Vernac, M. Pinard, E. Giacobino

Using a quantum theory for an ensemble of two-level atoms driven by a field in an optical cavity, we show that the spin associated with the atomic ensemble can be squeezed. Two kinds of squeezing are obtained: on the one hand, self-squeezing of the spin when the input field is a coherent one and the atomic ensemble exhibits a large nonlinearity; and on the other hand, squeezing transfer from an incoming squeezed field when the atomic ensemble has a quasilinear behavior.

Physical Review A•Nov 14, 2000•59 citations

Atom spin squeezing in a double lambda system

Aurélien Dantan, M. Pinard, P. R. Berman

The interaction of classical and quantized electromagnetic fields with an ensemble of atoms in an optical cavity is considered. Four fields drive a double-lambda level scheme in the atoms, consisting of a pair of lambda systems sharing the same set of lower levels. Two of the fields produce maximum coherence, rho12 = -1/2, between the ground state sublevels 1 and 2. This pumping scheme involves equal intensity fields that are resonant with both the one and two-photon transitions of the lambda system. There is no steady-state absorption of these fields, implying that the fields induce a type electromagnetically-induced transparency (EIT) in the medium. An additional pair of fields interacting with the second lambda system, combined with the EIT fields, leads to squeezing of the atom spin associated with the ground state sublevels. Our method involves a new mechanism for creating steady-state spin squeezing using an optical cavity. As the cooperativity parameter C is increased, the optimal squeezing varies as C^{-1/3}. For experimentally accessible values of C, squeezing as large as 90% can be achieved.

arXiv:quant-ph/0302012•Feb 2, 2003•0 citations

Atomic squeezing and quantum memory in a three-level system

Aurélien Dantan, M. Pinard, P. R. Berman

We study theoretically different schemes to generate long lived atomic squeezed states via the interaction between fields and an atomic ensemble in cavity. Spin squeezing may be achieved using coherent fields or squeezed vacuum fields

Conference on Lasers and Electro-Optics•Jan 1, 2004•0 citations

Electromagnetically induced squeezing of atomic spin

Xihua Yang, Xuping Shao, Mingfei Cheng

We present a special quantum effect named electromagnetically induced squeezing of atomic spin in the conventional Λ-type atomic system driven by a strong pump field and a relatively weak probe field in an atomic ensemble. Nearly perfect atomic spin squeezing in the y component can be achieved with fully on resonance at high pump-field intensity, large optical depth of the atomic ensemble, and a low coherence decay rate between the two lower levels. This method would greatly facilitate the generation of atomic spin squeezing by using only coherent laser fields, and may find potential applications in realistic quantum metrology, quantum computation, and quantum information processing.

Journal of Modern Optics•Apr 12, 2019•2 citations

Vacuum spin squeezing

Jiazhong Hu, Wenlan Chen, Zachary Vendeiro +3 more

We investigate the generation of entanglement (spin squeezing) in an optical-transition atomic clock through the coupling to an optical cavity in its vacuum state. We show that if each atom is prepared in a superposition of the ground state and a long-lived electronic excited state, and viewed as a spin-1/2 system, then the collective vacuum light shift entangles the atoms, resulting in a squeezed distribution of the ensemble collective spin, without any light applied. This scheme reveals that even an electromagnetic vacuum can constitute a useful resource for entanglement and quantum manipulation. By rotating the spin direction while coupling to the vacuum, the scheme can be extended to implement two-axis twisting resulting in stronger squeezing.

arXiv:1703.02439•Physical Review A•Nov 16, 2017•46 citations
Using a quantum theory for an ensemble of three-level atoms (\ensuremathΛ)(\ensuremath{\Lambda})(\ensuremathΛ) placed in an optical cavity and driven by electromagnetic fields, we show that the long-lived spin associated with the ground-state sublevels can be squeezed. Two kinds of squeezing are obtained: self-spin squeezing, when the input fields are coherent states and the atomic ensemble exhibits a large nonlinearity; squeezing transfer approaching 100%, when one of the incoming fields is squeezed.
The interaction of classical and quantized electromagnetic fields with an ensemble of atoms in an optical cavity is considered. Four fields drive a double-lambda level scheme in the atoms, consisting of a pair of lambda systems sharing the same set of lower levels. Two of the fields produce maximum coherence, rho12 = -1/2, between the ground state sublevels 1 and 2. This pumping scheme involves equal intensity fields that are resonant with both the one and two-photon transitions of the lambda system. There is no steady-state absorption of these fields, implying that the fields induce a type electromagnetically-induced transparency (EIT) in the medium. An additional pair of fields interacting with the second lambda system, combined with the EIT fields, leads to squeezing of the atom spin associated with the ground state sublevels. Our method involves a new mechanism for creating steady-state spin squeezing using an optical cavity. As the cooperativity parameter C is increased, the optimal squeezing varies as C^{-1/3}. For experimentally accessible values of C, squeezing as large as 90% can be achieved.
We present a special quantum effect named electromagnetically induced squeezing of atomic spin in the conventional Λ-type atomic system driven by a strong pump field and a relatively weak probe field in an atomic ensemble. Nearly perfect atomic spin squeezing in the y component can be achieved with fully on resonance at high pump-field intensity, large optical depth of the atomic ensemble, and a low coherence decay rate between the two lower levels. This method would greatly facilitate the generation of atomic spin squeezing by using only coherent laser fields, and may find potential applications in realistic quantum metrology, quantum computation, and quantum information processing.
We investigate the generation of entanglement (spin squeezing) in an optical-transition atomic clock through the coupling to an optical cavity in its vacuum state. We show that if each atom is prepared in a superposition of the ground state and a long-lived electronic excited state, and viewed as a spin-1/2 system, then the collective vacuum light shift entangles the atoms, resulting in a squeezed distribution of the ensemble collective spin, without any light applied. This scheme reveals that even an electromagnetic vacuum can constitute a useful resource for entanglement and quantum manipulation. By rotating the spin direction while coupling to the vacuum, the scheme can be extended to implement two-axis twisting resulting in stronger squeezing.