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Nonlinear Schrödinger wave equation with linear quantum behavior Richardson, Christopher ; Schlagheck, Peter ; Martin, John et al in Physical Review A (2014), 89 We show that a nonlinear Schroedinger wave equation can reproduce all the features of linear quantum mechanics. This nonlinear wave equation is obtained by exploring, in a uniform language, the transition ... [more ▼] We show that a nonlinear Schroedinger wave equation can reproduce all the features of linear quantum mechanics. This nonlinear wave equation is obtained by exploring, in a uniform language, the transition from fully classical theory governed by a nonlinear classical wave equation to quantum theory. The classical wave equation includes a nonlinear classicality enforcing potential which when eliminated transforms the wave equation into the linear Schro ̈dinger equation. We show that it is not necessary to completely cancel this nonlinearity to recover the linear behavior of quantum mechanics. Scaling the classicality enforcing potential is sufficient to have quantumlike features appear and is equivalent to scaling Planck’s constant. [less ▲] Detailed reference viewed: 29 (7 ULg)Highly non-classical symmetric states of an N-qubit system Baguette, Dorian ; Martin, John Poster (2013, September 02) In this work, we consider two measures of non-classicality for pure symmetric N-qubit states : Wehrl entropy (S) and Wehrl participation ratio (R). Measures of non-classicality help to the understanding ... [more ▼] In this work, we consider two measures of non-classicality for pure symmetric N-qubit states : Wehrl entropy (S) and Wehrl participation ratio (R). Measures of non-classicality help to the understanding of the mechanisms responsible for the transition from quantum to classical physics and are usefull in the context of information processing and quantum-enhanced measurements. [less ▲] Detailed reference viewed: 37 (8 ULg)Influence of dipole-dipole interactions on superradiance Damanet, François ; Martin, John Poster (2013, September 02) Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and ... [more ▼] Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and single photon cooperative emission [2]. The dissipative dynamics of the atoms is known to depend dramatically on the ratio between the typical inter- atomic distance and the atomic transition wavelength, notably because of dipole-dipole interactions [3]. In this work, we study the effects of these interactions on superradiance as in [4] by solving numerically the corresponding master equation. In particular, by averaging over many realizations of the randomly distributed atomic positions, we show that the decay of the radiated energy pulse height with the intensity of the dipolar coupling follows a power law. [1] E. Ackermans, A. Gero & R. Kaiser, Phys. Rev. Lett. 101, 103602 (2008). [2] R. Friedberg & J. T. Manassah, J. Phys. B 43, 035501 (2010). [3] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [4] B. Coffey & R. Friedberg, Phys. Rev. A 17, 1033 (1978). [less ▲] Detailed reference viewed: 76 (8 ULg)Multifractality of quantum wave functions ; ; et al Poster (2013, September) Detailed reference viewed: 27 (3 ULg)Influence of dipole-dipole interactions on the superradiant pulse Damanet, François ; Martin, John Poster (2013, May 23) Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and ... [more ▼] Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and single photon cooperative emission [2]. The dissipative dynamics of the atoms is known to depend dramatically on the ratio between the typical inter-atomic distance and the atomic transition wavelength, notably because of dipole-dipole interactions [3]. In this work, we study the effects of these interactions on superradiance as in [4] by solving numerically the corresponding master equation. In particular, by averaging over many realizations of the randomly distributed atomic positions, we show that the decay of the radiated energy pulse height with the intensity of the dipolar coupling follows a power law. [1] E. Ackermans, A. Gero & R. Kaiser, Phys. Rev. Lett. 101, 103602 (2008). [2] R. Friedberg & J. T. Manassah, J. Phys. B 43, 035501 (2010). [3] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [4] B. Coffey & R. Friedberg, Phys. Rev. A 17, 1033 (1978). [less ▲] Detailed reference viewed: 25 (6 ULg)The most non-classical symmetric states of an N-qubit system Baguette, Dorian ; Martin, John Poster (2013, May 23) Detailed reference viewed: 30 (5 ULg)Weakening of superradiance due to dipole-dipole interactions Damanet, François ; Martin, John Poster (2013, March 19) Detailed reference viewed: 31 (15 ULg)Highly non-classical symmetric states of an N-qubit system Baguette, Dorian ; Martin, John Poster (2013, March 19) Detailed reference viewed: 26 (10 ULg)Multifractality of quantum wave functions Martin, John ; ; et al Poster (2013, March 19) We study the multifractality of individual wave packets in a periodically kicked system through a combination of numerical and analytical works. We consider a version of the mathematical Ruijsenaars ... [more ▼] We study the multifractality of individual wave packets in a periodically kicked system through a combination of numerical and analytical works. We consider a version of the mathematical Ruijsenaars-Schneider model and reinterpreted it physically in order to describe the spreading with time of quantum wave packets in a system where multifractality can be tuned by varying a parameter [1]. We compare different methods to measure the multifractality of wave packets and identify the best one. We find the multifractality to decrease with time until it reaches an asymptotic limit, which is different from the multifractality of eigenvectors but related to it, as is the rate of the decrease. Our results could guide the study of experimental situations where multifractality is present in quantum systems. [less ▲] Detailed reference viewed: 29 (7 ULg)Artificial Abelian gauge potentials induced by dipole-dipole interactions between Rydberg atoms Cesa, Alexandre ; Martin, John in Physical Review. A (2013), 88 We analyze the influence of dipole-dipole interactions between Rydberg atoms on the generation of Abelian artificial gauge potentials and fields. When two Rydberg atoms are driven by a uniform laser field ... [more ▼] We analyze the influence of dipole-dipole interactions between Rydberg atoms on the generation of Abelian artificial gauge potentials and fields. When two Rydberg atoms are driven by a uniform laser field, we show that the combined atom-atom and atom-field interactions give rise to new, nonuniform, artificial gauge potentials. We identify the mechanism responsible for the emergence of these gauge potentials. Analytical expressions for the latter indicate that the strongest artificial magnetic fields are reached in the regime intermediate between the dipole blockade regime and the regime in which the atoms are sufficiently far apart such that atom-light interaction dominates over atom-atom interactions. We discuss the differences and similarities of artificial gauge fields originating from resonant dipole-dipole and van der Waals interactions. We also give an estimation of experimentally attainable artificial magnetic fields resulting from this mechanism and we discuss their detection through the deflection of the atomic motion. [less ▲] Detailed reference viewed: 119 (39 ULg)Multifractality of quantum wave packets ; Martin, John ; et al in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2012), 86 We study a version of the mathematical Ruijsenaars-Schneider model and reinterpret it physically in order to describe the spreading with time of quantum wave packets in a system where multifractality can ... [more ▼] We study a version of the mathematical Ruijsenaars-Schneider model and reinterpret it physically in order to describe the spreading with time of quantum wave packets in a system where multifractality can be tuned by varying a parameter. We compare different methods to measure the multifractality of wave packets and identify the best one. We find the multifractality to decrease with time until it reaches an asymptotic limit, which is different from the multifractality of eigenvectors but related to it, as is the rate of the decrease. Our results could guide the study of experimental situations where multifractality is present in quantum systems. [less ▲] Detailed reference viewed: 91 (4 ULg)The quest for highly entangled symmetric states Martin, John Scientific conference (2012, June 05) Detailed reference viewed: 23 (10 ULg)Heisenberg-limited Metrology without Entanglement ; Martin, John in Research in Optical Sciences, OSA Technical Digest (2012) Detailed reference viewed: 16 (3 ULg)Heisenberg-limited metrology without entanglement ; Martin, John Conference (2012, March) Detailed reference viewed: 11 (0 ULg)Heisenberg-limited metrology without entanglement ; Martin, John Conference (2012, January) Detailed reference viewed: 14 (2 ULg)Multiqubit symmetric states with a high geometric entanglement Martin, John ; ; et al Poster (2011, May 25) We propose a detailed study of the geometric entanglement properties of pure symmetric N-qubit states, focusing more particularly on the identification of symmetric states with a high geometric ... [more ▼] We propose a detailed study of the geometric entanglement properties of pure symmetric N-qubit states, focusing more particularly on the identification of symmetric states with a high geometric entanglement and how their entanglement behaves asymptotically for large N. We show that much higher geometric entanglement with improved asymptotical behavior can be obtained in comparison with the highly entangled balanced Dicke states studied previously. We also derive an upper bound for the geometric measure of entanglement of symmetric states. The connection with the quantumness of a state is discussed. [less ▲] Detailed reference viewed: 47 (10 ULg)Heisenberg-limited sensitivity with decoherence-enhanced measurements ; Martin, John in Nature Communications (2011), 2(223), 1-9 Quantum-enhanced measurements use quantum mechanical effects to enhance the sensitivity of the measurement of classical quantities, such as the length of an optical cavity. The major goal is to beat the ... [more ▼] Quantum-enhanced measurements use quantum mechanical effects to enhance the sensitivity of the measurement of classical quantities, such as the length of an optical cavity. The major goal is to beat the standard quantum limit (SQL), that is, an uncertainty of order 1/ N, where N is the number of quantum resources (for example, the number of photons or atoms used), and to achieve a scaling 1/N, known as the Heisenberg limit. So far very few experiments have demonstrated an improvement over the SQL. The required quantum states are generally highly entangled, difficult to produce, and very prone to decoherence. Here, we show that Heisenberg- limited measurements can be achieved without the use of entangled states by coupling the quantum resources to a common environment that can be measured at least in part. The method is robust under decoherence, and in fact the parameter dependence of collective decoherence itself can be used to reach a 1/N scaling. [less ▲] Detailed reference viewed: 81 (25 ULg)Multiqubit symmetric states with a high geometric entanglement Martin, John ; ; et al Poster (2010, July) Detailed reference viewed: 24 (9 ULg)Multifractality in the kicked rotator Martin, John ; ; et al Poster (2010, July) Detailed reference viewed: 34 (9 ULg)Multifractality in quantum maps Martin, John ; ; et al Poster (2010, March) Detailed reference viewed: 11 (4 ULg) |
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