Search results for "discord"

Sérologie discordante du VIH/sida et vie des couples en République du Congo : profil sociodémographique, comportements, facteurs de survie et prise e…

2020

For more than two decades, the health of populations has been at the heart of developmental issues. Population health issues fall within the "health, population and development" paradigm. It is in this spirit that experts demonstrated at the 1994 Cairo Conference on Population and Development that HIV/AIDS affects both population growth and sustainable development. Likewise, HIV infection is a source of discrimination, social inequalities, and the weakening of couples and families to the point where some individuals are even ostracized because of their HIV-positive status. In these conditions, how do people of different serological status live their married lives and their procreation despi…

Genuine quantum and classical correlations in multipartite systems

2011

PACS numbers: 03.67.Mn, 03.65.Ud

Entanglement Theory with Continuous Variables

2016

Observability of the sign of wave functions

1976

A change of the phase factor of -1 in the wave function of a molecular quantum system leads to observable consequences in transition probabilities between molecular quantum states in accordance with quantum-mechanical calculations.

Optical control of entangled states in semiconductor quantum wells

2012

We present theory and calculations for coherent high-fidelity quantum control of many-particle states in semiconductor quantum wells. We show that coupling a two-electron double quantum dot to a terahertz optical source enables targeted excitations that are one to two orders of magnitude faster and significantly more accurate than those obtained with electric gates. The optical fields subject to physical constraints are obtained through quantum optimal control theory that we apply in conjunction with the numerically exact solution of the time-dependent Schrödinger equation. Our ability to coherently control arbitrary two-electron states, and to maximize the entanglement, opens up further pe…

Multidimensional quantum walks: Diabolical points, optical wave-like propagation, and multipartite entanglement

2013

Quantum walks (QWs) are important for quantum information science, but are becoming also interesting for other fields of research as this simple quantum diffusion model finds analogues in diverse physical systems, optical ones in particular. The experimental capabilities regarding QWs have remarkably increased along recent years and several aspects of QWs are now open to experimental research, multidimensional QWs in particular [1].

Steering distillation processes through quantum Zeno dynamics

2005

A quantum system in interaction with a repeatedly measured one undergoes a nonunitary time evolution and is pushed into a subspace substantially determined by the two-system coupling. The possibility of suitably modifying such an evolution through quantum Zeno dynamics (i.e., the generalized quantum Zeno effect) addressing the system toward an a priori decided target subspace is illustrated. Applications and their possible realizations in the context of trapped ions are also discussed.

Quantum control and long-range quantum correlations in dynamical Casimir arrays

2015

The recent observation of the dynamical Casimir effect in a modulated superconducting waveguide, coronating thirty years of world-wide research, empowered the quantum technology community with a powerful tool to create entangled photons on-chip. In this work we show how, going beyond the single waveguide paradigm using a scalable array, it is possible to create multipartite nonclassical states, with the possibility to control the long-range quantum correlations of the emitted photons. In particular, our finite-temperature theory shows how maximally entangled $NOON$ states can be engineered in a realistic setup. The results here presented open the way to new kinds of quantum fluids of light,…

Multi-State Quantum Dissipative Dynamics in Sub-Ohmic Environment: The Strong Coupling Regime

2015

We study the dissipative quantum dynamics and the asymptotic behavior of a particle in a bistable potential interacting with a sub-Ohmic broadband environment. The reduced dynamics, in the intermediate to strong dissipation regime, is obtained beyond the two-level system approximation by using a real-time path integral approach. We find a crossover dynamic regime with damped intra-well oscillations and incoherent tunneling and a completely incoherent regime at strong damping. Moreover, a nonmonotonic behavior of the left/right well population difference is found as a function of the damping strength.

Quantum correlations in generalized spin star system

2006

The problem of detecting quantum signatures in the correlations formed in dynamical evolution of quantum bipartite systems receives a lot of attention in current literature. Generally speaking, the occurrence of correlations between two observables of a system does not necessarily reflect nonclassical behaviour. In this paper, the exact dynamics of a pair of uncoupled spins 1/2 interacting with a common spin 1/2 bath is investigated. Starting from a separable initial condition, the ability of the system to develop purely quantum correlations is brought to light. Physical interpretation of the concurrence function as well as a suggestion on how to measure it are given.