We discuss two qualities of quantum systems: various correlations existing between their subsystems and the distinguishability of different quantum states. This is then applied to analysing quantum information processing. While quantum correlations, or entanglement, are clearly of paramount importance for efficient pure state manipulations, mixed states present a much richer arena and reveal a more subtle interplay between correlations and distinguishability. The current work explores a number of issues related with identifying the important ingredients needed for quantum information processing. We (...) discuss the Deutsch-Jozsa algorithm, the Shor algorithm, the Grover algorithm and the power of a single qubit class of algorithms. In the latter, a quantity called discord is seen to be more important than entanglement. One section is dedicated to cluster states where entanglement is crucial, but its precise role is highly counter-intuitive. Here we see that the notion of distinguishability becomes a more useful concept. (shrink)

In this paper we argue that one-way quantum computation can be seen as a form of phase transition with the available information about the solution of the computation being the order parameter. We draw a number of striking analogies between standard thermodynamical quantities such as energy, temperature, work, and corresponding computational quantities such as the amount of entanglement, time, potential capacity for computation, respectively. Aside from being intuitively pleasing, this picture allows us to make novel conjectures, such as an estimate (...) of the necessary critical time to finish a computation and a proposal of suitable architectures for universal one-way computation in 1D. (shrink)

In the paper, the author deals with the history of attempts to defame integrative bioethics by a group of Croatian philosophers and incidental media appearances in which the tendency was to slander the long-standing research concept of the Zagreb bioethics school. In the introduction, a historical overview of the basic qualitative and quantitative results of integrative bioethics in the Croatian and European context is given. This is followed by an analysis of the context of defamation of integrative bioethics and the (...) actors of defamation, separated according to “scientific” and media content. Finally, the attempt to compromise and profane integrative bioethics is interpreted as part of the destrolution phenomenon, the theory of post-communist chaos and the production of fake envy. (shrink)

A recent paper by Rieper, Anders and Vedral (arxiv.org/abs/1006.4053: The Relevance Of Continuous Variable Entanglement In DNA) suggests that quantum entanglement among base pairs in the DNA double helix stabilizes the molecule. A summary of their paper is reported in MIT Technology Review (http://www.technologyreview.com/blog/arxiv/25375/) is below..

In the seminal works from Santos and Gozalo and Marletto and Vedral, it is shown how the Aharonov–Bohm effect can be described as the result of an exchange of virtual photons between the solenoid and the quantum charged particle along its propagation through the interferometer, where both the particle and the solenoid interact locally with the quantum electromagnetic field. This interaction results in a local and gauge-independent phase generation for the particle propagation in each path of the interferometer. Here (...) we improve the cited treatments by using the quantum electrodynamics formalism in the Lorentz gauge, with a manifestly gauge-independent Hamiltonian for the interaction and the presence of virtual longitudinal photons. Only with this more complete and gauge-independent treatment it is possible to justify the acquired phases for interferometers with arbitrary geometries. We also extend the results to the electric version of the Aharonov–Bohm effect. Finally, we propose an experiment that could test the locality of the Aharonov–Bohm phase generation. (shrink)