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Related papers: Four Photon Entanglement from Down Conversion

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We investigate a method to produce photon pairs by four-wave mixing in photonic crystal fibers (PCFs). By controlling the wavelength of the pump light, which determines the phase matching condition for four-wave mixing, we can obtain a…

Quantum Physics · Physics 2011-06-16 Toshihiro Nakanishi , Kazuo Sakemi , Hirokazu Kobayashi , Kazuhiko Sugiyama , Masao Kitano

Entangled photons are a crucial resource for quantum communication and linear optical quantum computation. Unfortunately, the applicability of many photon-based schemes is limited due to the stochastic character of the photon sources.…

Quantum Physics · Physics 2012-02-07 Stefanie Barz , Gunther Cronenberg , Anton Zeilinger , Philip Walther

We investigate duality in entanglement of a bipartite multi-photon system generated from a coherent state of light. The system can exhibit polarization entanglement if the two parts are distinguished by their parity, or parity entanglement…

Quantum Physics · Physics 2016-08-17 Su-Yong Lee , Chang-Woo Lee , Pawel Kurzynski , Dagomir Kaszlikowski , Jaewan Kim

We report on the experimental observation and characterization of a six-photon entangled Dicke state. We obtain a fidelity as high as 0.654$\pm$0.024 and prove genuine six-photon entanglement by, amongst others, a two-setting witness…

We show that electron recombination using positively charged excitons in single quantum dots provides an efficient method to transfer entanglement from electron spins onto photon polarizations. We propose a scheme for the production of…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Veronica Cerletti , Oliver Gywat , Daniel Loss

We experimentally generate and characterize a six-photon polarization entangled state, which is usually called "Psi 6 +". This is realized with a filtering procedure of triple emissions of entangled photon pairs from a single source, which…

Quantum Physics · Physics 2009-10-12 Magnus Radmark , Marek Zukowski , Mohamed Bourennane

We study the quantum correlations of the radiation emitted by three level atoms (cascade type) interacting with two driving fields. In the linear regime, and in the Weisskopf-Wigner approximation, we show that the atomic and the two-photon…

Quantum Physics · Physics 2010-12-30 S. N. Sandhya , V. Ravishankar

Entangled photon pairs are key to many novel applications in quantum technologies. Semiconductor quantum dots can be used as sources of on-demand, highly entangled photons. The fidelity to a fixed maximally entangled state is limited by the…

A single linear optical set-up is used to observe an entire family of four-photon entangled states. This approach breaks with the inflexibility of present linear-optical set-ups usually designed for the observation of a particular…

The generation of entangled photon pairs by parametric down--conversion from solid state CW lasers with small coherence time is theoretically and experimentally analyzed. We consider a compact and low-cost setup based on a two-crystal…

Quantum Physics · Physics 2009-04-16 Simone Cialdi , Fabrizio Castelli , Matteo G. A. Paris

We consider the scattering of entangled two-photon states from collections of small particles. We also study the related Mie problem of scattering from a sphere. In both cases, we calculate the entropy of entanglement and investigate the…

Optics · Physics 2016-04-20 John C. Schotland , A. Caze , Theodore B. Norris

We study the interference structure of the second-order intensity correlation function for polarization-entangled two-photon light obtained from type-II collinear frequency-degenerate spontaneous parametric down-conversion (SPDC). The…

Quantum Physics · Physics 2009-11-13 G. Brida , M. V. Chekhova , M. Genovese , L. A. Krivitsky

Entanglement [1, 2] enables powerful new quantum technologies [3-8], but in real-world implementations, entangled states are often subject to decoherence and preparation errors. Entanglement distillation [9, 10] can often counteract these…

Quantum Physics · Physics 2010-09-24 Jonathan Lavoie , Rainer Kaltenbaek , Marco Piani , Kevin J. Resch

Space momentum entangled photon pairs are generated from type II parametric down conversion in a beta barium borate crystal. The correlations in the positions of photons in the near field and far field planes with regard to the generating…

Quantum Physics · Physics 2015-05-13 Martin Ostermeyer , Dietmar Korn , Dirk Puhlmann

Entangled photons can be used to make measurements with an accuracy beyond that possible with classical light. While most implementations of quantum metrology have used states made up of a single colour of photons, we show that entangled…

We use polarization-entangled photon pairs to demonstrate quantum nonlocality in an experiment suitable for advanced undergraduates. The photons are produced by spontaneous parametric downconversion using a violet diode laser and two…

Quantum Physics · Physics 2009-11-07 Dietrich Dehlinger , M. W. Mitchell

A sufficient condition for entanglement in two-mode continuous systems is constructed based on interference visibility and the uncertainty of the total particle number. The observables to be measured (particle numbers and particle number…

Quantum Physics · Physics 2007-05-23 Geza Toth , Christoph Simon , Juan Ignacio Cirac

Photons entangled in their position-momentum degrees of freedom (DoFs) serve as an elegant manifestation of the Einstein-Podolsky-Rosen paradox, while also enhancing quantum technologies for communication, imaging, and computation. The…

We address the process of generation of the photon-number entangled states of light in the stimulated nonlinear parametric down conversion process and build the simple model describing the generation, not involving the traditional…

Quantum Physics · Physics 2010-03-02 Oleksandr O. Gurin , Vladyslav C. Usenko , Constantin V. Usenko

An experiment is performed where a single rubidium atom trapped within a high-finesse optical cavity emits two independently triggered entangled photons. The entanglement is mediated by the atom and is characterized both by a Bell…

Quantum Physics · Physics 2009-01-26 B. Weber , H. P. Specht , T. Mueller , J. Bochmann , M. Muecke , D. L. Moehring , G. Rempe