[en] In a recent paper Sanpera et al. have shown, that for the simplest binary composite systems any density matrix can be described in terms of only product vectors. The purpose of this note is to show that possibility of decomposing any state as pseudo mixtures does not depend on dimension of the subsystems. (author)

[en] A Comment on the Letter by D.I. Bradley, Phys.Rev.Lett.84, 1252 (2000). The authors of the Letter offer a Reply

[en] A Reply to the Comment by Michael Miemetz, Wilfried Schoepe, and M. Krasius

No abstract available

[en] Nonlinear data search algorithms proposed recently by Abrams and Lloyd are fast but make an explicit use of an arbitrarily fast unphysical transfer of information within a quantum computer. It is shown that the algorithms can be described also in a fully local formalism. (author)

[en] A secure quantum identification system combining a classical identification procedure and quantum key distribution is proposed. Each identification sequence is always used just once and new sequences are 're fuelled' from a shared secret key transferred over a quantum channel. The question of authentication of information sent over a public channel is discussed. An apparatus using two unbalanced Mach-Zehnder interferometers has been built, and quantum key distribution and 'quantum identification' have been successfully tested through a single-mode optical fibre at 830 nm, employing low intensity coherent states (below 0,1 photons per pulse). (author)

[en] The anomalies that appear at every multiple of 15 .deg. C in the viscosity of a thin liquid film of water and of water near solid interfaces are explained in this paper by comparing the thermal wavelength and molecular free volume of water, and quantum numbers are found. The possibility that these anomalies are related to the preferred and/or lethal temperatures of organisms is considered. The toxicity of heavy water (D₂O) can also be explained with this approach

No abstract available

[en] The potential of a slowly moving test charge in a quantum plasma is deduced. It is shown that, besides the Debye-Hueckel near-field potential, there is a far-field potential which decays as the inverse cube of the distance between the origin of the test charge and the location of the observer

[en] We will consider a Fermi liquid system with weak interaction, where total rotational symmetry is assumed. We will restrict ourselves to sufficiently low temperatures kT << ε_F, which is fulfilled in real systems. In accordance with that, the energy and momentum of Landau quasi-particles can be taken solely from the Fermi sphere or its vicinity. (orig.)