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33
Sep 21, 2013
09/13
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K. S. Choi; H. Deng; J. Laurat; H. J. Kimble
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Recent developments of quantum information science critically rely on entanglement, an intriguing aspect of quantum mechanics where parts of a composite system can exhibit correlations stronger than any classical counterpart. In particular, scalable quantum networks require capabilities to create, store, and distribute entanglement among distant matter nodes via photonic channels. Atomic ensembles can play the role of such nodes. So far, in the photon counting regime, heralded entanglement...
Source: http://arxiv.org/abs/0712.3571v2
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7.0
Jun 26, 2018
06/18
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B. Gouraud; D. Maxein; A. Nicolas; O. Morin; J. Laurat
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eye 7
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We report the experimental observation of slow-light and coherent storage in a setting where light is tightly confined in the transverse directions. By interfacing a tapered optical nanofiber with a cold atomic ensemble, electromagnetically induced transparency is observed and light pulses at the single-photon level are stored in and retrieved from the atomic medium with an overall efficiency of (10 +/- 0.5) %. Collapses and revivals can be additionally controlled by an applied magnetic field....
Topics: Quantum Physics, Optics, Physics
Source: http://arxiv.org/abs/1502.01458
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11
Jun 30, 2018
06/18
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K. Huang; H. Le Jeannic; J. Ruaudel; O. Morin; J. Laurat
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eye 11
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Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and...
Topics: Physics, Quantum Physics, Optics, Instrumentation and Detectors
Source: http://arxiv.org/abs/1409.3675
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28
Sep 21, 2013
09/13
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M. Scherman; O. S. Mishina; P. Lombardi; E. Giacobino; J. Laurat
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Electromagnetically-induced transparency has become an important tool to control the optical properties of dense media. However, in a broad class of systems, the interplay between inhomogeneous broadening and the existence of several excited levels may lead to a vanishing transparency. Here, by identifying the underlying physical mechanisms resulting in this effect, we show that transparency can be strongly enhanced. We thereby demonstrate a 5-fold enhancement in a room-temperature vapor of...
Source: http://arxiv.org/abs/1106.0988v3
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40
Sep 24, 2013
09/13
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T. Golubeva; Yu. Golubev; O. Mishina; A. Bramati; J. Laurat; E. Giacobino
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We present a general model for an atomic memory using ultra-short pulses of light, which allows both spatial and temporal multimode storage. The process involves the storage of a faint quantum light pulse into the spin coherence of the ground state of Lambda-type 3-level atoms, in the presence of a strong driving pulse. Our model gives a full description of the evolution of the field and of the atomic coherence in space and time throughout the writing and the read-out processes. It is valid for...
Source: http://arxiv.org/abs/1112.4852v1
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71
Sep 17, 2013
09/13
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J. Cviklinski; J. Ortalo; J. Laurat; A. Bramati; M. Pinard; E. Giacobino
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Using Electromagnetically Induced Transparency (EIT) in a Cesium vapor, we demonstrate experimentally that the quantum state of a light beam can be mapped into the long lived Zeeman coherences of an atomic ground state. Two non-commuting variables carried by light are simultaneously stored and subsequentely read-out, with no noise added. We compare the case where a tunable single sideband is stored independently of the other one to the case where the two symmetrical sidebands are stored using...
Source: http://arxiv.org/abs/0711.0264v2
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3.0
Jun 27, 2018
06/18
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V. Parigi; V. D'Ambrosio; C. Arnold; L. Marrucci; F. Sciarrino; J. Laurat
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eye 3
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The full structuration of light in the transverse plane, including intensity, phase and polarization, holds the promise of unprecedented capabilities for applications in classical optics as well as in quantum optics and information sciences. Harnessing special topologies can lead to enhanced focusing, data multiplexing or advanced sensing and metrology. Here we experimentally demonstrate the storage of such spatio-polarization-patterned beams into an optical memory. A set of vectorial vortex...
Topics: Quantum Physics, Optics, Physics
Source: http://arxiv.org/abs/1504.03096
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59
Sep 23, 2013
09/13
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T. Golubeva; Yu. Golubev; O. Mishina; A. Bramati; J. Laurat; E. Giacobino
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We study the coherent storage and retrieval of a very short multimode light pulse in an atomic ensemble. We consider a quantum memory process based on the conversion of a signal pulse into a long-lived spin coherence via light matter interaction in an on-resonant Lambda-type system. In order to study the writing and reading processes we analytically solve the partial differential equations describing the evolution of the field and of the atomic coherence in time as well as in space. We show how...
Source: http://arxiv.org/abs/1012.5016v4
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55
Sep 21, 2013
09/13
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J. Laurat; K. S. Choi; H. Deng; C. W. Chou; H. J. Kimble
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Heralded entanglement between collective excitations in two atomic ensembles is probabilistically generated, stored, and converted to single photon fields. By way of the concurrence, quantitative characterizations are reported for the scaling behavior of entanglement with excitation probability and for the temporal dynamics of various correlations resulting in the decay of entanglement. A lower bound of the concurrence for the collective atomic state of 0.9\pm 0.3 is inferred. The decay of...
Source: http://arxiv.org/abs/0706.0528v2
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2.0
Jun 30, 2018
06/18
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A. S. Sheremet; D. F. Kornovan; L. V. Gerasimov; B. Gouraud; J. Laurat; D. V. Kupriyanov
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Light transport in a dense and disordered cold atomic ensemble, where the cooperation of atomic dipoles essentially modifies their coupling with the radiation modes, offers an alternative approach to light-matter interfacing protocols. Here, we show how the cooperativity and quasi-static dipole interaction affect the process of light propagation under the conditions of electromagnetically-induced transparency (EIT). We perform comparative analysis of the self-consistent approach with ab-initio...
Topic: Quantum Physics
Source: http://arxiv.org/abs/1411.4771
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49
Sep 23, 2013
09/13
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L. Veissier; A. Nicolas; L. Giner; D. Maxein; A. S. Sheremet; E. Giacobino; J. Laurat
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We report on an experiment in which orbital angular momentum of light is mapped at the single-photon level into and out of a cold atomic ensemble. Based on the dynamic electromagnetically-induced transparency protocol, the demonstrated optical memory enables the reversible mapping of Laguerre-gaussian modes with preserved handedness of the helical phase structure. The demonstrated capability opens the possibility to the storage of qubits encoded as superpositions of orbital angular momentum...
Source: http://arxiv.org/abs/1212.2382v2
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45
Sep 18, 2013
09/13
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H. de Riedmatten; J. Laurat; C. W. Chou; E. W. Schomburg; D. Felinto; H. J. Kimble
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eye 45
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Violations of a Bell inequality are reported for an experiment where one of two entangled qubits is stored in a collective atomic memory for a user-defined time delay. The atomic qubit is found to preserve the violation of a Bell inequality for storage times up to 21 microseconds, 700 times longer than the duration of the excitation pulse that creates the entanglement. To address the question of the security of entanglement-based cryptography implemented with this system, an investigation of...
Source: http://arxiv.org/abs/quant-ph/0606249v2
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70
Jul 20, 2013
07/13
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D. Felinto; C. W. Chou; J. Laurat; E. W. Schomburg; H. de Riedmatten; H. J. Kimble
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eye 70
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Quantum networks hold the promise for revolutionary advances in information processing with quantum resources distributed over remote locations via quantum-repeater architectures. Quantum networks are composed of nodes for storing and processing quantum states, and of channels for transmitting states between them. The scalability of such networks relies critically on the ability to perform conditional operations on states stored in separated quantum memories. Here we report the first...
Source: http://arxiv.org/abs/quant-ph/0609191v2
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39
Sep 18, 2013
09/13
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J. Laurat; C. W. Chou; H. Deng; K. S. Choi; D. Felinto; H. de Riedmatten; H. J. Kimble
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eye 39
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We present a protocol for performing entanglement connection between pairs of atomic ensembles in the single excitation regime. Two pairs are prepared in an asynchronous fashion and then connected via a Bell measurement. The resulting state of the two remaining ensembles is mapped to photonic modes and a reduced density matrix is then reconstructed. Our observations confirm for the first time the creation of coherence between atomic systems that never interacted, a first step towards...
Source: http://arxiv.org/abs/0704.2246v1
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4.0
Jun 29, 2018
06/18
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N. V. Corzo; B. Gouraud; A. Chandra; A. Goban; A. S. Sheremet; D. V. Kupriyanov; J. Laurat
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We report experimental observations of large Bragg reflection from arrays of cold atoms trapped near a one-dimensional nanoscale waveguide. By using an optical lattice in the evanescent field surrounding a nanofiber with a period nearly commensurate with the resonant wavelength, we observe a reflectance of up to 75% for the guided mode. Each atom behaves as a partially-reflecting mirror and an ordered chain of about 2000 atoms is sufficient to realize an efficient Bragg mirror. Measurements of...
Topics: Atomic Physics, Quantum Physics, Optics, Physics
Source: http://arxiv.org/abs/1604.03129
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2.0
Jun 29, 2018
06/18
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H. Le Jeannic; V. B. Verma; A. Cavaillès; F. Marsili; M. D. Shaw; K. Huang; O. Morin; S. W. Nam; J. Laurat
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eye 2
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We report on high-efficiency superconducting nanowire single-photon detectors based on amorphous WSi and optimized at 1064 nm. At an operating temperature of 1.8 K, we demonstrated a 93% system detection efficiency at this wavelength with a dark noise of a few counts per second. Combined with cavity-enhanced spontaneous parametric down-conversion, this fiber-coupled detector enabled us to generate narrowband single photons with a heralding efficiency greater than 90% and a high spectral...
Topics: Quantum Physics, Optics, Physics, Instrumentation and Detectors
Source: http://arxiv.org/abs/1607.07459
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43
Sep 22, 2013
09/13
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O. S. Mishina; M. Scherman; P. Lombardi; J. Ortalo; D. Felinto; A. S. Sheremet; A. Bramati; D. V. Kupriyanov; J. Laurat; E. Giacobino
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eye 43
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Electromagnetically induced transparency (EIT) has mainly been modelled for three-level systems. In particular, a considerable interest has been dedicated to the Lambda-configuration, with two ground states and one excited state. However, in the alkali-metal atoms, which are commonly used, hyperfine interaction in the excited state introduces several levels which simultaneously participate in the scattering process. When the Doppler broadening is comparable with the hyperfine splitting in the...
Source: http://arxiv.org/abs/1101.6039v4
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2.0
Jun 28, 2018
06/18
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K. Huang; H. Le Jeannic; V. B. Verma; M. D. Shaw; F. Marsili; S. W. Nam; E Wu; H. Zeng; O. Morin; J. Laurat
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eye 2
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Conditional preparation is a well-established technique for quantum state engineering of light. A general trend is to increase the number of heralding detection events in such realization to reach larger photon-number states or their arbitrary superpositions. In contrast to pulsed implementations, where detections only occur within the pulse window, for continuous-wave light the temporal separation of the conditioning detections is an additional degree of freedom and a critical parameter. Based...
Topic: Quantum Physics
Source: http://arxiv.org/abs/1511.02122
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5.0
Jun 27, 2018
06/18
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K. Huang; H. Le Jeannic; J. Ruaudel; V. B. Verma; M. D. Shaw; F. Marsili; S. W. Nam; E Wu; H. Zeng; Y. -C. Jeong; R. Filip; O. Morin; J. Laurat
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eye 5
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We propose and experimentally realize a novel versatile protocol that allows the quantum state engineering of heralded optical coherent-state superpositions. This scheme relies on a two-mode squeezed state, linear mixing and a $n$-photon detection. It is optimally using expensive non-Gaussian resources to build up only the key non-Gaussian part of the targeted state. In the experimental case of a two-photon detection based on high-efficiency superconducting nanowire single-photon detectors, the...
Topic: Quantum Physics
Source: http://arxiv.org/abs/1503.08970
