The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Ugo Marzolino - One of the best experts on this subject based on the ideXlab platform.
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remarks on entanglement and Identical Particles
Open Systems & Information Dynamics, 2017Co-Authors: Fabio Benatti, Roberto Floreanini, Flaminia Franchini, Ugo MarzolinoAbstract:We argue that in the case of Identical Particles the most natural identification of separability, that is of absence of non-classical correlations, is via the factorization of mean values of commuting observables. It thus follows that separability and entanglement depend both on the state and on the choice of observables and are not absolute notions. We compare this point of view with a recent novel approach to the entanglement of Identical Particles, which allows for the definition of an entanglement entropy from a suitably defined reduced particle density matrix, without the need of labelling the system constituents. We contrast this figure of merit with the aforementioned lack of an absolute notion of entanglement by considering few paradigmatic examples.
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entanglement robustness and geometry in systems of Identical Particles
Physical Review A, 2012Co-Authors: Fabio Benatti, Roberto Floreanini, Ugo MarzolinoAbstract:The robustness properties of bipartite entanglement in systems of N bosons distributed in M different modes are analyzed using a definition of separability based on commuting algebras of observables, a natural choice when dealing with Identical Particles. Within this framework, expressions for the robustness and generalized robustness of entanglement can be explicitly given for large classes of boson states: their entanglement content results in general much more stable than that of distinguishable Particles states. Using these results, the geometrical structure of the space of N boson states can be explicitly addressed.
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entanglement and squeezing with Identical Particles ultracold atom quantum metrology
Journal of Physics B, 2011Co-Authors: Fabio Benatti, Roberto Floreanini, Ugo MarzolinoAbstract:In quantum metrological applications based on ultracold atom systems, entangled initial states are thought necessary to achieve sub-shot-noise accuracies. This conclusion, although strictly true for systems of distinguishable Particles, does no longer hold for systems of Identical Particles. Indeed, while quantum non-locality is necessary, it can be encoded into the interferometric apparatus and not into the initial states. In particular, no preliminary spin-squeezing is necessary to reach quantum performances in metrological applications of ultracold atom physics.
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sub shot noise quantum metrology with entangled Identical Particles
Annals of Physics, 2010Co-Authors: Fabio Benatti, Roberto Floreanini, Ugo MarzolinoAbstract:The usual notion of separability has to be reconsidered when applied to states describing Identical Particles. A definition of separability not related to any a priori Hilbert space tensor product structure is needed: this can be given in terms of commuting subalgebras of observables. Accordingly, the results concerning the use of the quantum Fisher information in quantum metrology are generalized and physically reinterpreted.
Giuseppe Compagno - One of the best experts on this subject based on the ideXlab platform.
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activating remote entanglement in a quantum network by local counting of Identical Particles
Physical Review A, 2019Co-Authors: Alessia Castellini, Giuseppe Compagno, Bruno Bellomo, Rosario Lo FrancoAbstract:Quantum information and communication processing within quantum networks usually employs Identical Particles. Despite this, the physical role of quantum statistical nature of Particles in large-scale networks remains elusive. Here, we show that just the indistinguishability of fermions makes it possible a new mechanism of entanglement transfer in many-node quantum networks. This process activates remote entanglement among distant sites, which do not share a common past, by only locally counting Identical Particles and classical communication. These results constitute the key achievement of the present technique and open the way to a more stable multistage transfer of nonlocal quantum correlations based on fermions.
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quantum entanglement of Identical Particles by standard information theoretic notions
Scientific Reports, 2016Co-Authors: Rosario Lo Franco, Giuseppe CompagnoAbstract:Quantum entanglement of Identical Particles is essential in quantum information theory. Yet, its correct determination remains an open issue hindering the general understanding and exploitation of many-particle systems. Operator-based methods have been developed that attempt to overcome the issue. Here we introduce a state-based method which, as second quantization, does not label Identical Particles and presents conceptual and technical advances compared to the previous ones. It establishes the quantitative role played by arbitrary wave function overlaps, local measurements and particle nature (bosons or fermions) in assessing entanglement by notions commonly used in quantum information theory for distinguishable Particles, like partial trace. Our approach furthermore shows that bringing Identical Particles into the same spatial location functions as an entangling gate, providing fundamental theoretical support to recent experimental observations with ultracold atoms. These results pave the way to set and interpret experiments for utilizing quantum correlations in realistic scenarios where overlap of Particles can count, as in Bose-Einstein condensates, quantum dots and biological molecular aggregates.
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Quantum entanglement of Identical Particles by standard information-theoretic notions
Scientific Reports, 2016Co-Authors: Rosario Lo Franco, Giuseppe CompagnoAbstract:Quantum entanglement of Identical Particles is essential in quantum information theory. Yet, its correct determination remains an open issue hindering the general understanding and exploitation of many-particle systems. Operator-based methods have been developed that attempt to overcome the issue. We introduce a state-based method which, as second quantization, does not label Identical Particles and presents conceptual and technical advances compared to the previous ones. It establishes the quantitative role played by arbitrary wave function overlaps, local measurements and particle nature (bosons or fermions) in assessing entanglement by notions commonly used in quantum information theory for distinguishable Particles, like partial trace. Our approach furthermore shows that bringing Identical Particles into the same spatial location functions as an entangling gate, providing fundamental theoretical support to recent experimental observations with ultracold atoms. These results pave the way to set and interpret experiments for utilizing quantum correlations in realistic scenarios where overlap of Particles can count, as in Bose-Einstein condensates, quantum dots and biological molecular aggregates.
Fabio Benatti - One of the best experts on this subject based on the ideXlab platform.
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remarks on entanglement and Identical Particles
Open Systems & Information Dynamics, 2017Co-Authors: Fabio Benatti, Roberto Floreanini, Flaminia Franchini, Ugo MarzolinoAbstract:We argue that in the case of Identical Particles the most natural identification of separability, that is of absence of non-classical correlations, is via the factorization of mean values of commuting observables. It thus follows that separability and entanglement depend both on the state and on the choice of observables and are not absolute notions. We compare this point of view with a recent novel approach to the entanglement of Identical Particles, which allows for the definition of an entanglement entropy from a suitably defined reduced particle density matrix, without the need of labelling the system constituents. We contrast this figure of merit with the aforementioned lack of an absolute notion of entanglement by considering few paradigmatic examples.
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entanglement robustness and geometry in systems of Identical Particles
Physical Review A, 2012Co-Authors: Fabio Benatti, Roberto Floreanini, Ugo MarzolinoAbstract:The robustness properties of bipartite entanglement in systems of N bosons distributed in M different modes are analyzed using a definition of separability based on commuting algebras of observables, a natural choice when dealing with Identical Particles. Within this framework, expressions for the robustness and generalized robustness of entanglement can be explicitly given for large classes of boson states: their entanglement content results in general much more stable than that of distinguishable Particles states. Using these results, the geometrical structure of the space of N boson states can be explicitly addressed.
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entanglement and squeezing with Identical Particles ultracold atom quantum metrology
Journal of Physics B, 2011Co-Authors: Fabio Benatti, Roberto Floreanini, Ugo MarzolinoAbstract:In quantum metrological applications based on ultracold atom systems, entangled initial states are thought necessary to achieve sub-shot-noise accuracies. This conclusion, although strictly true for systems of distinguishable Particles, does no longer hold for systems of Identical Particles. Indeed, while quantum non-locality is necessary, it can be encoded into the interferometric apparatus and not into the initial states. In particular, no preliminary spin-squeezing is necessary to reach quantum performances in metrological applications of ultracold atom physics.
-
sub shot noise quantum metrology with entangled Identical Particles
Annals of Physics, 2010Co-Authors: Fabio Benatti, Roberto Floreanini, Ugo MarzolinoAbstract:The usual notion of separability has to be reconsidered when applied to states describing Identical Particles. A definition of separability not related to any a priori Hilbert space tensor product structure is needed: this can be given in terms of commuting subalgebras of observables. Accordingly, the results concerning the use of the quantum Fisher information in quantum metrology are generalized and physically reinterpreted.
Rosario Lo Franco - One of the best experts on this subject based on the ideXlab platform.
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activating remote entanglement in a quantum network by local counting of Identical Particles
Physical Review A, 2019Co-Authors: Alessia Castellini, Giuseppe Compagno, Bruno Bellomo, Rosario Lo FrancoAbstract:Quantum information and communication processing within quantum networks usually employs Identical Particles. Despite this, the physical role of quantum statistical nature of Particles in large-scale networks remains elusive. Here, we show that just the indistinguishability of fermions makes it possible a new mechanism of entanglement transfer in many-node quantum networks. This process activates remote entanglement among distant sites, which do not share a common past, by only locally counting Identical Particles and classical communication. These results constitute the key achievement of the present technique and open the way to a more stable multistage transfer of nonlocal quantum correlations based on fermions.
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n Identical Particles and one particle to entangle them all
Physical Review A, 2017Co-Authors: Bruno Bellomo, Rosario Lo Franco, G CompagnoAbstract:In quantum information W states are a central class of multipartite entangled states because of their robustness against noise and use in many quantum processes. Their generation however remains a demanding task whose difficulty increases with the number of Particles. We report a simple scalable conceptual scheme where a single particle in an ancilla mode works as entanglement catalyst of W state for other $N$ separated Identical Particles. A crucial novel aspect of the scheme, which exploits basically spatial indistinguishability, is its universality, being applicable without essential changes to both bosons and fermions. Our proposal represents a new paradigm within experimental preparation of many-particle entanglement based on quantum indistinguishability.
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quantum entanglement of Identical Particles by standard information theoretic notions
Scientific Reports, 2016Co-Authors: Rosario Lo Franco, Giuseppe CompagnoAbstract:Quantum entanglement of Identical Particles is essential in quantum information theory. Yet, its correct determination remains an open issue hindering the general understanding and exploitation of many-particle systems. Operator-based methods have been developed that attempt to overcome the issue. Here we introduce a state-based method which, as second quantization, does not label Identical Particles and presents conceptual and technical advances compared to the previous ones. It establishes the quantitative role played by arbitrary wave function overlaps, local measurements and particle nature (bosons or fermions) in assessing entanglement by notions commonly used in quantum information theory for distinguishable Particles, like partial trace. Our approach furthermore shows that bringing Identical Particles into the same spatial location functions as an entangling gate, providing fundamental theoretical support to recent experimental observations with ultracold atoms. These results pave the way to set and interpret experiments for utilizing quantum correlations in realistic scenarios where overlap of Particles can count, as in Bose-Einstein condensates, quantum dots and biological molecular aggregates.
L. F. Lemmens - One of the best experts on this subject based on the ideXlab platform.
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Path Integrals and Statistics of Identical Particles
Foundations of Physics, 2020Co-Authors: J. T. Devreese, F. Brosens, L. F. LemmensAbstract:We summarize the essential ingredients, which enabled us to derive the path-integral for a system of harmonically interacting spin-polarized Identical Particles in a parabolic confining potential, including both the statistics (Bose–Einstein or Fermi–Dirac) and the harmonic interaction between the Particles. This quadratic model, giving rise to repetitive Gaussian integrals, allows to derive an analytical expression for the generating function of the partition function. The calculation of this generating function circumvents the constraints on the summation over the cycles of the permutation group. Moreover, it allows one to calculate the canonical partition function recursively for the system with harmonic two-body interactions. Also, static one-point and two-point correlation functions can be obtained using the same technique, which make the model a powerful trial system for further variational treatments of realistic interactions.
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Thermodynamics and Path Integrals for Identical Particles: the Formalism
International Journal of Modern Physics B, 2001Co-Authors: F. Brosens, L. F. Lemmens, J. T. DevreeseAbstract:A generalization of symmetrized density matrices in combination with the technique of generating functions allows to calculate the partition function and the static correlation functions of Identical Particles in a parabolic confining well with harmonic two-body interactions.
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density and pair correlation function of confined Identical Particles the bose einstein case
Physical Review E, 1997Co-Authors: F. Brosens, J. T. Devreese, L. F. LemmensAbstract:Two basic correlation functions are calculated for a model of N harmonically interacting Identical Particles in a parabolic potential well. The density and the pair correlation function of the model are investigated for the boson case. The dependence of these static response properties on the complete range of the temperature and of the number of Particles is obtained. The calculation technique is based on the path integral approach of symmetrized density matrices for Identical Particles in a parabolic confining well. {copyright} {ital 1997} {ital The American Physical Society}
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Many-body diffusion and path integrals for Identical Particles.
Physical Review E, 1996Co-Authors: L. F. Lemmens, F. Brosens, J. T. DevreeseAbstract:For distinguishable Particles it is well known that Brownian motion and a Feynman-Kac functional can be used to calculate the path integral (for imaginary times) for a general class of scalar potentials. In order to treat Identical Particles, we exploit the fact that this method separates the problem of the potential, dealt with by the Feynman-Kac functional, from the process which gives sample paths of a noninteracting system. For motion in one dimension, we emphasize that the permutation symmetry of the Identical Particles completely determines the domain of Brownian motion and the appropriate boundary conditions: absorption for fermions, reflection for bosons. Further analysis of the sample paths for motion in three dimensions allows us to decompose these paths into a superposition of one-dimensional sample paths. This reduction expresses the propagator (and consequently the energy and other thermodynamical quantities) in terms of well-behaved one-dimensional fermion and boson diffusion processes and the Feynman-Kac functional.