Quantum Entanglement is widely regarded as one of the most prominent features of quantum mechanics and quantum information science. Although, photonic entanglement is routinely studied in many experiments nowadays, its signature has been out of the grasp for real-time imaging. Here we show that modern technology, namely triggered intensified charge coupled device (ICCD) cameras are fast and sensitive enough to image in real-time the effect of the measurement of one photon on its entangled partner. To quantitatively verify the non-classicality of the measurements we determine the detected photon number and error margin from the registered intensity image within a certain region. Additionally, the use of the ICCD camera allows us to demonstrate the high flexibility of the setup in creating any desired spatial-mode entanglement, which suggests as well that visual imaging in quantum optics not only provides a better intuitive understanding of entanglement but will improve applications of quantum science.
Quantum orbital angular momentum of elliptically symmetric light
William N. Plick,
Mario Krenn,
Robert Fickler,
Sven Ramelow,
Anton Zeilinger
Physical Review A
87
(3)
033806
(2013)
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We present a quantum-mechanical analysis of the orbital angular momentum of a class of recently discovered elliptically symmetric stable light fields-the so-called Ince-Gauss modes. We study, in a fully quantum formalism, how the orbital angular momentum of these beams varies with their ellipticity, and we discover several compelling features, including nonmonotonic behavior, stable beams with real continuous (noninteger) orbital angular momenta, and orthogonal modes with the same orbital angular momenta. We explore, and explain in detail, the reasons for this behavior. These features may have applications in quantum key distribution, atom trapping, and quantum informatics in general-as the ellipticity opens up an alternative way of navigating the spatial photonic Hilbert space. DOI: 10.1103/PhysRevA.87.033806
Entangled singularity patterns of photons in Ince-Gauss modes
Mario Krenn,
Robert Fickler,
Marcus Huber,
Radek Lapkiewicz,
William Plick,
Sven Ramelow,
Anton Zeilinger
Physical Review A
87
(1)
012326
(2013)
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Photons with complex spatial mode structures open up possibilities for new fundamental high-dimensional quantum experiments and for novel quantum information tasks. Here we show entanglement of photons with complex vortex and singularity patterns called Ince-Gauss modes. In these modes, the position and number of singularities vary depending on the mode parameters. We verify two-dimensional and three-dimensional entanglement of Ince-Gauss modes. By measuring one photon and thereby defining its singularity pattern, we nonlocally steer the singularity structure of its entangled partner, while the initial singularity structure of the photons is undefined. In addition we measure an Ince-Gauss specific quantum-correlation function with possible use in future quantum communication protocols. DOI: 10.1103/PhysRevA.87.012326
Kontakt
Junior Forschungsgruppe Mario Krenn
Max-Planck-Institut für die Physik des Lichts Staudtstr. 2 91058 Erlangen
