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Quantum discord: a measure of the quantumness of correlations.
This work shows that absence of entanglement does not imply classicality, and considers the vanishing of discord as a criterion for the preferred effectively classical states of a system, i.e., the pointer states. Expand
Dark halos formed via dissipationless collapse. I: Shapes and alignment of angular momentum
We use N-body simulations on highly parallel supercomputers to study the structure of Galactic dark matter halos. The systems form by gravitational collapse from scale-free and more general GaussianExpand
Decoherence, einselection, and the quantum origins of the classical
as quantum engineering. In the past two decades it has become increasingly clear that many (perhaps all) of the symptoms of classicality can be induced in quantum systems by their environments. ThusExpand
A single quantum cannot be cloned
If a photon of definite polarization encounters an excited atom, there is typically some nonvanishing probability that the atom will emit a second photon by stimulated emission. Such a photon isExpand
Cosmological experiments in superfluid helium?
Symmetry breaking phase transitions occurring in the early Universe are expected to leave behind long-lived topologically stable structures such as monopoles, strings or domain walls1–6. Here IExpand
Decoherence and the Transition from Quantum to Classical—Revisited
The environment surrounding a quantum system can, in effect, monitor some of the systems observables. As a result, the eigenstates of these observables continuously decohere and can behave likeExpand
Pointer Basis of Quantum Apparatus: Into What Mixture Does the Wave Packet Collapse?
The form of the interaction Hamiltonian between the apparatus and its environment is sufficient to determine which observable of the measured quantum system can be considered "recorded" by theExpand
Quantum Darwinism
Quantum Darwinism describes the proliferation, in the environment, of multiple records of selected states of a quantum system. It explains how the fragility of a state of a single quantum system canExpand
Environment-induced superselection rules
We show how the correlations of a quantum system with other quantum systems may cause one of its observables to behave in a classical manner. In particular, "reduction of the wave packet," postulatedExpand
The Environment, Decoherence and the Transition from Quantum to Classical
Quantum mechanics works exceedingly well in all practical applications. No example of conflict between its predictions and experiment is known. Without quantum physics we could not explain theExpand