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

Quantum-Atom Optics Downunder (QAO)

Estimation of Three-Dimensional Entanglement between an Atomic Ensemble and a Photon

Ryotaro Inoue, T. Yonehara, Y. Miyamoto, Masato Koashi, Mikio Kozuma

Published Jan 1, 2007• 0 citations
Publisher

Abstract

Controlling the orbital angular momentum state opens the door to the manipulation of arbitrarily large dimensional quantum state. Here we propose a new method to estimate the Schmidt number of the quantum state. The method enables us to avoid a problem appearing when we estimate the entanglement on the orbital angular momentum of photons using phase holograms. We also report the experimental results on the atoms-photon entanglement which was analyzed by the proposed method. Our experimental results show the possibility of controlling and entangling two remote massive atoms with higher dimensional basis.

DOI
10.1364/qao.2007.qwe18

Related papers

Measuring Qutrit-Qutrit Entanglement of Orbital Angular Momentum States of an Atomic Ensemble and a Photon

Ryotaro Inoue, T. Yonehara, Y. Miyamoto +2 more

Three-dimensional entanglement of orbital angular momentum states of an atomic qutrit and a single photon qutrit has been observed. Their full state was reconstructed using quantum state tomography. The fidelity to the maximally entangled state of Schmidt rank 3 exceeds the threshold 2/3. This result confirms that the density matrix cannot be decomposed into an ensemble of pure states of Schmidt rank 1 or 2. That is, the Schmidt number of the density matrix must be equal to or greater than 3.

arXiv:0903.2903•Physical Review Letters•Sep 11, 2009•81 citations

How to create and detect N-dimensional entangled photons with an active phase hologram

Martin Stütz, Simon Gröblacher, Thomas D. Jennewein +1 more

The experimental realization of multidimensional quantum states may lead to unexplored and interesting physics, as well as advanced quantum communication protocols. The orbital angular momentum of photons is a well suitable discrete degree of freedom for implementing high-dimensional quantum systems. The standard method to generate and manipulate such photon modes is to use bulk and fixed optics. Here the authors demonstrate the utilization of a spatial light modulator to manipulate the orbital angular momentum of entangled photons generated in spontaneous parametric downconversion. They show that their setup allows them to realize photonic entanglement of up to 21 dimensions, which in principle can be extended to even larger dimensions.

arXiv:0707.0061•Applied Physics Letters•Jun 25, 2007•44 citations

Entanglement of orbital angular momentum states between an ensemble of cold atoms and a photon

Ryotaro Inoue, Nobuhiro Kanai, T. Yonehara +3 more

Recently, atomic ensemble and single photons were successfully entangled by using collective enhancement [D. N. Matsukevich et al., Phys. Rev. Lett. 95, 040405 (2005)], where atomic internal states and photonic polarization states were correlated in a nonlocal manner. Here, we experimentally clarified that in an ensemble of atoms and a photon system, there also exists an entanglement concerned with spatial degrees of freedom. Generation of higher-dimensional entanglement between remote atomic ensemble and an application to condensed matter physics are also discussed.

arXiv:quant-ph/0604165•Physical Review A•Nov 15, 2006•85 citations

Mode counting in high-dimensional orbital angular momentum entanglement

Martin P. van Exter, Wouter H. J. Peeters, J. P. Woerdman

We demonstrate experimentally how the orbital angular momentum (OAM) entanglement within a photon pair can be fully characterized with a two-photon interferometer that contains an image rotator. The Schmidt number of the OAM entanglement can be tuned between 1 and 8.

The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting•Jan 1, 2007•1 citation

Entanglement of the orbital angular momentum states of the photon pairs generated in a hot atomic ensemble

Qunfeng Chen, Bao‐Sen Shi, Yong-Sheng Zhang +1 more

In this paper, we experimentally demonstrate that the photon pairs generated via spontaneous four-wave mixing in a hot atomic ensemble are in entangled orbital angular momentum (OAM) states. The density matrix of the OAM states of the photon pair is reconstructed, from which the fidelity to the maximal entangled state and the concurrence are estimated to be about 0.89 and 0.81, respectively. The experimental result also suggests the existence of the entanglement concerned with spatial degrees of freedom between the hot atomic ensemble and the Stokes photon.

arXiv:0807.0130•Physical Review A•Nov 6, 2008•92 citations

Quantum Entanglement of High Angular Momenta

Robert Fickler, Radek Łapkiewicz, William N. Plick +4 more

Single photons with helical phase structures may carry a quantized amount of orbital angular momentum (OAM), and their entanglement is important for quantum information science and fundamental tests of quantum theory. Because there is no theoretical upper limit on how many quanta of OAM a single photon can carry, it is possible to create entanglement between two particles with an arbitrarily high difference in quantum number. By transferring polarization entanglement to OAM with an interferometric scheme, we generate and verify entanglement between two photons differing by 600 in quantum number. The only restrictive factors toward higher numbers are current technical limitations. We also experimentally demonstrate that the entanglement of very high OAM can improve the sensitivity of angular resolution in remote sensing.

arXiv:1207.2376•Science•Nov 1, 2012•848 citations
Controlling the orbital angular momentum state opens the door to the manipulation of arbitrarily large dimensional quantum state. Here we propose a new method to estimate the Schmidt number of the quantum state. The method enables us to avoid a problem appearing when we estimate the entanglement on the orbital angular momentum of photons using phase holograms. We also report the experimental results on the atoms-photon entanglement which was analyzed by the proposed method. Our experimental results show the possibility of controlling and entangling two remote massive atoms with higher dimensional basis.
The experimental realization of multidimensional quantum states may lead to unexplored and interesting physics, as well as advanced quantum communication protocols. The orbital angular momentum of photons is a well suitable discrete degree of freedom for implementing high-dimensional quantum systems. The standard method to generate and manipulate such photon modes is to use bulk and fixed optics. Here the authors demonstrate the utilization of a spatial light modulator to manipulate the orbital angular momentum of entangled photons generated in spontaneous parametric downconversion. They show that their setup allows them to realize photonic entanglement of up to 21 dimensions, which in principle can be extended to even larger dimensions.
Recently, atomic ensemble and single photons were successfully entangled by using collective enhancement [D. N. Matsukevich et al., Phys. Rev. Lett. 95, 040405 (2005)], where atomic internal states and photonic polarization states were correlated in a nonlocal manner. Here, we experimentally clarified that in an ensemble of atoms and a photon system, there also exists an entanglement concerned with spatial degrees of freedom. Generation of higher-dimensional entanglement between remote atomic ensemble and an application to condensed matter physics are also discussed.
In this paper, we experimentally demonstrate that the photon pairs generated via spontaneous four-wave mixing in a hot atomic ensemble are in entangled orbital angular momentum (OAM) states. The density matrix of the OAM states of the photon pair is reconstructed, from which the fidelity to the maximal entangled state and the concurrence are estimated to be about 0.89 and 0.81, respectively. The experimental result also suggests the existence of the entanglement concerned with spatial degrees of freedom between the hot atomic ensemble and the Stokes photon.
Single photons with helical phase structures may carry a quantized amount of orbital angular momentum (OAM), and their entanglement is important for quantum information science and fundamental tests of quantum theory. Because there is no theoretical upper limit on how many quanta of OAM a single photon can carry, it is possible to create entanglement between two particles with an arbitrarily high difference in quantum number. By transferring polarization entanglement to OAM with an interferometric scheme, we generate and verify entanglement between two photons differing by 600 in quantum number. The only restrictive factors toward higher numbers are current technical limitations. We also experimentally demonstrate that the entanglement of very high OAM can improve the sensitivity of angular resolution in remote sensing.