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:1106.6205

Macroscopic Bell States and the Higher-Order Degree of Polarization

T. Sh. Iskhakov, I. N. Agafonov, Maria V. Chekhova, Georgy O. Rytikov, Gerd Leuchs

Published Jun 30, 2011• 0 citations
arXivHTMLPDF

Abstract

We study polarization properties of the macroscopic analogues of two-photon Bell states. The effect of hidden polarization, i.e., polarization in the second (and higher) orders in the intensity is observed for the triplet states while the singlet one is demonstrated to be nearly unpolarized at least up to the fourth order. The arbitrary-order degree of polarization is introduced and applied to the macroscopic Bell states.

DOI
10.48550/arxiv.1106.6205

Related papers

Polarization properties of macroscopic Bell states

T. Sh. Iskhakov, I. N. Agafonov, Maria V. Chekhova +2 more

The four two-photon polarization Bell states are one of the main instruments in the toolbox of quantum optics and quantum information. In our experiment we produce their multiphoton counterparts, macroscopic Bell states. These are relevant to applications in quantum technologies because they provide efficient interactions with material quantum objects and with each other via nonlinear interactions. Furthermore, we study the polarization properties of these states using the concept of second-order degree of polarization and its higher-order generalization.

Physical Review A•Oct 6, 2011•19 citations

Entanglement of macroscopic Bell states

T. Sh. Iskhakov, Bhaskar Kanseri, Georgy O. Rytikov +2 more

In this work we focus our attention on the correlation properties of a new class of bright nonclassical states of light, which are called the macroscopic Bell states [1,2]. These states are of interest in quantum optics due to their rarely combined two properties: brightness and quantumness. Recently we have investigated the polarization properties of these states, namely we have shown that the macroscopic singlet state is absolutely unpolarized and free of polarization noise [2], while the triplet states reveal the effect of hidden polarization [3]. Now we experimentally prove that both singlet and triplet macroscopic Bell states are entangled.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•May 1, 2013•0 citations

Macroscopic Bell States and their Quantum Polarization Tomography

Bhaskar Kanseri, T. Sh. Iskhakov, Maria V. Chekhova +1 more

Using three-dimensional quantum polarization tomography, the polarization properties of macroscopic Bell states are characterized. The reconstructed polarization quasi-probability distributions demonstrate squeezing in one or more Stokes parameters.

Conference on Lasers and Electro-Optics•Jan 1, 2012•0 citations

Unpolarized states and hidden polarization

Pablo de la Hoz, Gunnar G. Bjork, A. B. Klimov +2 more

We capitalize on a multipolar expansion of the polarization density matrix, in which multipoles appear as successive moments of the Stokes variables. When all the multipoles up to a given order $K$ vanish, we can properly say that the state is $K\mathrm{th}$-order unpolarized, as it lacks of polarization information to that order. First-order unpolarized states coincide with the corresponding classical ones, whereas unpolarized to any order tally with the quantum notion of fully invariant states. In between these two extreme cases, there is a rich variety of situations that are explored here. The existence of hidden polarization emerges in a natural way in this context.

arXiv:1409.7486•Physical Review A•Oct 15, 2014•19 citations

Three-dimensional quantum polarization tomography of macroscopic Bell states

Bhaskar Kanseri, T. Sh. Iskhakov, I. N. Agafonov +2 more

The polarization properties of macroscopic Bell states are characterized using three-dimensional quantum polarization tomography. This method utilizes three-dimensional (3D) inverse Radon transform to reconstruct the polarization quasiprobability distribution function of a state from the probability distributions measured for various Stokes observables. The reconstructed 3D distributions obtained for the macroscopic Bell states are compared with those obtained for a coherent state with the same mean photon number. The results demonstrate squeezing in one or more Stokes observables.

arXiv:1112.4282•Physical Review A•Feb 29, 2012•22 citations

Polarization of light: Fourth-order effects and polarization-squeezed states

D. M. Klyshko

The polarization properties of a monochromatic beam of light are ordinarily determined by three numbers, for example, the Stokes parameters. However, three numbers are no longer sufficient when intensity fluctuations in the polarized modes (or the correlation between them) are recorded. It is shown that in this case nine parameters, which can be arranged into 3×3 matrices, must be prescribed. The transformation properties of these matrices under polarization converters and the invariants of the matrices are analyzed. Specifically, the fourth-order polarization P 4 is introduced. Several examples are examined of light with “hidden” polarization—light which is not polarized in the ordinary sense ( P 2 =0) but is polarized in fourth order ( P 4 ≠0)—as well as “polarization-squeezed” light in which the quantum fluctuations of the Stokes parameters are suppressed.

Journal of Experimental and Theoretical Physics•Jun 1, 1997•77 citations
We study polarization properties of the macroscopic analogues of two-photon Bell states. The effect of hidden polarization, i.e., polarization in the second (and higher) orders in the intensity is observed for the triplet states while the singlet one is demonstrated to be nearly unpolarized at least up to the fourth order. The arbitrary-order degree of polarization is introduced and applied to the macroscopic Bell states.
The four two-photon polarization Bell states are one of the main instruments in the toolbox of quantum optics and quantum information. In our experiment we produce their multiphoton counterparts, macroscopic Bell states. These are relevant to applications in quantum technologies because they provide efficient interactions with material quantum objects and with each other via nonlinear interactions. Furthermore, we study the polarization properties of these states using the concept of second-order degree of polarization and its higher-order generalization.
In this work we focus our attention on the correlation properties of a new class of bright nonclassical states of light, which are called the macroscopic Bell states [1,2]. These states are of interest in quantum optics due to their rarely combined two properties: brightness and quantumness. Recently we have investigated the polarization properties of these states, namely we have shown that the macroscopic singlet state is absolutely unpolarized and free of polarization noise [2], while the triplet states reveal the effect of hidden polarization [3]. Now we experimentally prove that both singlet and triplet macroscopic Bell states are entangled.
We capitalize on a multipolar expansion of the polarization density matrix, in which multipoles appear as successive moments of the Stokes variables. When all the multipoles up to a given order KKK vanish, we can properly say that the state is KthK\mathrm{th}Kth-order unpolarized, as it lacks of polarization information to that order. First-order unpolarized states coincide with the corresponding classical ones, whereas unpolarized to any order tally with the quantum notion of fully invariant states. In between these two extreme cases, there is a rich variety of situations that are explored here. The existence of hidden polarization emerges in a natural way in this context.
The polarization properties of macroscopic Bell states are characterized using three-dimensional quantum polarization tomography. This method utilizes three-dimensional (3D) inverse Radon transform to reconstruct the polarization quasiprobability distribution function of a state from the probability distributions measured for various Stokes observables. The reconstructed 3D distributions obtained for the macroscopic Bell states are compared with those obtained for a coherent state with the same mean photon number. The results demonstrate squeezing in one or more Stokes observables.
The polarization properties of a monochromatic beam of light are ordinarily determined by three numbers, for example, the Stokes parameters. However, three numbers are no longer sufficient when intensity fluctuations in the polarized modes (or the correlation between them) are recorded. It is shown that in this case nine parameters, which can be arranged into 3×3 matrices, must be prescribed. The transformation properties of these matrices under polarization converters and the invariants of the matrices are analyzed. Specifically, the fourth-order polarization P 4 is introduced. Several examples are examined of light with “hidden” polarization—light which is not polarized in the ordinary sense ( P 2 =0) but is polarized in fourth order ( P 4 ≠0)—as well as “polarization-squeezed” light in which the quantum fluctuations of the Stokes parameters are suppressed.