Papers by Guido Bellomo
We present a complete review of the quantum-to-classical limit of open systems by means of the th... more We present a complete review of the quantum-to-classical limit of open systems by means of the theory of decoherence and the use of the Weyl- Wigner-Moyal (WWM) transformation. We show that the analytical ex- tension of the Hamiltonian provides a set of poles that can be used to (a) explain the non-unitary evolution of the relevant system and (b) com- pletely de?ne the set of preferred states that constitute the mixture into which the system decoheres: the Moving Preferred Basis. Moreover, we show that the WWM of these states are the best candidates to obtain the trajectories in the classical phase-space.
International Journal of Quantum Information, 2015
We argue that the dimensionality of the space of quantum systems' states should be considered as ... more We argue that the dimensionality of the space of quantum systems' states should be considered as a legitimate resource for quantum information tasks. The assertion is supported by the fact that quantum states with discord-like capacities can be obtained from classically correlated states in spaces of dimension large enough. We illustrate things with some simple examples that justify our claim.
We present a complete review of the quantum-to-classical limit of open systems by means of the th... more We present a complete review of the quantum-to-classical limit of open systems by means of the theory of decoherence and the use of the Weyl- Wigner-Moyal (WWM) transformation. We show that the analytical ex- tension of the Hamiltonian provides a set of poles that can be used to (a) explain the non-unitary evolution of the relevant system and (b) com- pletely de?ne the set of preferred states that constitute the mixture into which the system decoheres: the Moving Preferred Basis. Moreover, we show that the WWM of these states are the best candidates to obtain the trajectories in the classical phase-space.
The European Physical Journal D, 2014
In [2014 Eur.J.Phys. D 68 1], Hou, Huang, and Cheng present, using Tsallis' entropy, possible gen... more In [2014 Eur.J.Phys. D 68 1], Hou, Huang, and Cheng present, using Tsallis' entropy, possible generalizations of the quantum discord measure, finding original results. As for the mutual informations and discord, we show here that these two types of quantifiers can take negative values. In the two qubits instance we further determine in which regions they are non-negative. Additionally, we study alternative generalizations on the basis of Renyi entropies.
Advances in Mathematical Physics, 2015
Fisher's information measure plays a very important role in diverse areas of theoretical physics.... more Fisher's information measure plays a very important role in diverse areas of theoretical physics. The associated measures and , as functionals of quantum probability distributions defined in, respectively, coordinate and momentum spaces, are the protagonists of our present considerations. The product has been conjectured to exhibit a nontrivial lower bound in Hall . More explicitly, this conjecture says that for any pure state of a particle in one dimension ≥ 4. We show here that such is not the case. This is illustrated, in particular, for pure states that are solutions to the free-particle Schrödinger equation. In fact, we construct a family of counterexamples to the conjecture, corresponding to time-dependent solutions of the free-particle Schrödinger equation. We also conjecture that any normalizable time-dependent solution of this equation verifies → 0 for → ∞.
ABSTRACT We recently showed that a ring of two bistable oscillators is capable of storing a singl... more ABSTRACT We recently showed that a ring of two bistable oscillators is capable of storing a single bit of information via stochastic resonance. Memory performance was characterized in terms of the probability of erroneous bit detection and was shown to be minimized for a range of noise intensities. Furthermore, memory persistence was also shown to exhibit a stochastic‐resonance behavior. In this paper we investigate the influence on memory performance, in particular its resilience to noise, on both noise bandwidth and the limited time response of the bistable elements. We show that, for broad ranges of ST and noise bandwidths, the probability of erroneous bit retrieval is also minimized for an optimal noise intensity, exhibiting a deep well as a function of noise intensity. We are interested in the breadth of such a well as it points out to the robustness of the memory device under different working conditions. Moreover, we show that there exists a relation between the noise and ST bandwidths that favors wide wells. We believe that this relation may be of relevance as a design rule for practical memory devices sustained by noise.
Physics Letters A, 2011
In this paper we extend our investigations on noise-assisted storage devices through the experime... more In this paper we extend our investigations on noise-assisted storage devices through the experimental study of a loop composed of a single Schmitt trigger and an element that introduces a finite delay. We show that such a system allows the storage of several bits and does so more efficiently for an intermediate range of noise intensities. Finally, we study the probability of erroneous information retrieval as a function of elapsed time and show a way for predicting device performance independently of the number of stored bits.
Physica A: Statistical Mechanics and its Applications, 2014
Consider a bipartite quantum system with at least one of its two components being itself a compos... more Consider a bipartite quantum system with at least one of its two components being itself a composite system. By tracing over part of one (or both) of these two subsystems it is possible to obtain a reduced (separable) state that exhibits quantum correlations even if the original state of the full system is endowed only with classical correlations. This effect, first pointed out by Li and Luo in [PRA 78, 024303 (2008)], is of considerable interest because there is a growing body of evidence suggesting that quantum correlations in non-entangled, mixed states may constitute a useful resource to implement non trivial information related tasks. Here we conduct a systematic exploration of the aforementioned effect for particular families of states of quantum systems of low dimensionality (three qubits states). In order to assess the non-classicality of the correlations of the reduced states we use an indicator of quantum correlations based upon the state disturbances generated by the measurement of local observables. We show, for a three-qubit system, that there exists a relationship between the classical mutual information of the original classically correlated states and the maximum quantum correlation exhibited by the reduced states.
In this article, we discuss the formal structure of a generalized information theory based on the... more In this article, we discuss the formal structure of a generalized information theory based on the extension of the probability calculus of Kolmogorov to a (possibly) non-commutative setting. By studying this framework, we argue that quantum information can be considered as a particular case of a huge family of non-commutative extensions of its classical counterpart. In any conceivable information theory, the possibility of dealing with different kinds of information measures plays a key role. Here, we generalize a notion of state spectrum, allowing us to introduce a majorization relation and a new family of generalized entropic measures.
articles by Guido Bellomo
phdtheses by Guido Bellomo
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Papers by Guido Bellomo
articles by Guido Bellomo
phdtheses by Guido Bellomo