Schr\"odinger's pure-state steering completed

Schroedinger investigated entanglement in two-particle state vectors by assuming measurement finding out if the nearby particle is in a given state vector or not. Without interaction with the distant particle, just on account of the entanglement, the distant particle is steered into a certain state vector. In Schroedinger's finite-dimensional case thus any distant-particle state vector can be reached. This theory was extended to infinite-dimensional spaces by the author. The present article completes the extension by throwing light on the fine structure of steering.Comment: 10 pages, Latex2e, no figure

Type-II Superconductivity in Ternary Zirconium Pnictide Chalcogenide Single Crystals

Layered Pnictides are proven to be a great reservoir for superconductors in the past and ternary zirconium pnictide chalcogenides of ZrXY-type (X = P, As; Y = S, Se) might be a platform for new superconductors. The superconducting properties of carefully grown (chemical transport reaction) single crystals of ZrP1.54S0.46 with a transition temperature of Tc = 3.5 K are investigated. This compound (PbFCl structure type) contains square planar nets: One of the nets is completely occupied (no vacancies) by P, the other one characterized by a random distribution of P and S (full occupation: no vacancies). Besides zero-field-cooling (zfc), field-cooling (fc), and remanent moment (rem) measurements, especially magnetization and ac susceptibility measurements are performed. A nearly ideal type-II behavior with a Ginzburg-Landau parameter κ = 24 is found. The magnetization curves between Bc1 and Bc2 for increasing field are in excellent agreement with theoretical calculations performed by E. H. Brandt based on the Ginzburg-Landau theory. The decreasing branches of the magnetization curves are asymmetric about the field axis indicating weak pinning and also large diamagnetic behavior

Estudio farmacocinético de propofol en equinos

Se estudian las características farmacocinéticas de propofol en 6 caballos. Se determinaron parámetros farmacocinéticos de propofol cuantificando sus concentraciones sanguíneas en función del tiempo por HPLC, tras su administración de 2.4 mg/kg por vía endovenosa al grupo de animales. Los datos de concentración se interpretaron por un modelo abierto de 2 compartimentos, obteniéndose, entre otros, los valores de t1/2a, t1/2b,Vdc, Vdss, Vdb, Cltotaly MRT. Las variables farmacodinámicas se encuentran acordes a la disposición cinética de este fármaco. El análisisde los parámetros farmacocinéticos del propofol indica que éste posee una rápida y pronta distribución a los tejidos y una rápida eliminación del organismo. El propofol se presenta como una alternativa anestésica factible de ser incorporada dentro de un protocolo anestésico en caballos. Los parámetros farmacocinéticos obtenidos contribuyen para una correcta dosificación ya sea para mantener un estado de anestesia por infusión continua o por inyecciones repetidasPharmacokinetic variables of propofol were studied in 6 horses. Blood concentration of propofol at different times, after a single dose of 2.4mg/kg bw, was determined by HPLC. An open two compartment model was used to evaluate blood concentrations of propofol. Values of t1/2a,t1/2b, Vdc, Vdss,Vdb, Cltotal y MRT were obtained.The pharmacodynamic values show a narrow relationship with the pharmacokinetic disposition of this drug. Propofol s pharmacokinetic disposition presented a rapid distribution and removal from organic tissues. It is concluded that propofol is an alternative to be considered in anaesthetic protocolsin horses, and the pharmacokinetic variables presented contribute to determinethe appropriate dose to be give

Chains of Quasi-Classical Informations for Bipartite Correlations and the Role of Twin Observables

Having the quantum correlations in a general bipartite state in mind, the information accessible by simultaneous measurement on both subsystems is shown never to exceed the information accessible by measurement on one subsystem, which, in turn is proved not to exceed the von Neumann mutual information. A particular pair of (opposite- subsystem) observables are shown to be responsible both for the amount of quasi-classical correlations and for that of the purely quantum entanglement in the pure-state case: the former via simultaneous subsystem measurements, and the latter through the entropy of coherence or of incompatibility, which is defined for the general case. The observables at issue are so-called twin observables. A general definition of the latter is given in terms of their detailed properties.Comment: 7 pages, Latex2e, selected for the December 2002 issue of the Virtual Journal of Quantum Informatio

Farmacocinética de propofol en potrillos de 10 a 15 días de edad

Se estudian las características farmacocinéticas de propofol en 6 potrillos de 10 a 15 días de edad. Se determinaron parámetros farmacocinéticos de propofol, cuantificando sus concentraciones sanguíneas en función del tiempo por HPLC, tras su administración de 2,4 mg/kg por vía endovenosa al grupo de animales. Los datos de concentración se interpretaron por un modelo abierto de 2 compartimentos, obteniéndose, entre otros, los valores de t1/2a, t1/2b, Vdc, Vdss, Vdb, Cltotal y MRT. El análisis de los parámetros farmacocinéticos del propofol, indican que éste posee una rápida y pronta distribución a los tejidos y una rápida eliminación del organismo. Los parámetros farmacocinéticos obtenidos contribuyen a efectuar cálculos para una correcta dosificaciónPharmacokinetic variables of propofol were studied in 8 foals. Plasma levels of propofol at different time after a single intravenous dose of 2.4 mg/kg bw, were determined by HPLC. An open two compartments model was used to evaluate plasma levels of propofol and values of t1/2a, t1/2b, Vdc, Vdss, Vdb, Cltotal y MRT were obtained. Propofol pharmacokinetic disposition showed a rapid distribution and removal from organic tissues, and the reported pharmacokinetic variables contribute to determine the appropriate dose to be give

Mixed-state twin observables

Twin observables, i.e. opposite subsystem observables A+ and A- that are indistinguishable in measurement in a given mixed or pure state W, are investigated in detail algebraicly and geometrically. It is shown that there is a far-reaching correspondence between the detectable (in W) spectral entities of the two operators. Twin observables are state-dependently quantum-logically equivalent, and direct subsystem measurement of one of them ipso facto gives rise to the indirect (i.e. distant) measurement of the other. Existence of nontrivial twins requires singularity of W. Systems in thermodynamic equilibrium do not admit subsystem twins. These observables may enable one to simplify the matrix representing W.Comment: 13 page

Strong Correlations in Electron Doped Phthalocyanine Conductors Near Half Filling

We propose that electron doped nontransition metal-phthalocyanines (MPc) like ZnPc and MgPc, similar to those very recently reported, should constitute novel strongly correlated metals. Due to orbital degeneracy, Jahn-Teller coupling and Hund's rule exchange, and with a large on-site Coulomb repulsion, these molecular conductors should display, particularly near half filling at two electrons/molecule, very unconventional properties, including Mott insulators, strongly correlated superconductivity, and other intriguing phases.Comment: 4 pages, 1 figure, submited to PR

Derivation of the quantum probability law from minimal non-demolition measurement

One more derivation of the quantum probability rule is presented in order to shed more light on the versatile aspects of this fundamental law. It is shown that the change of state in minimal quantum non-demolition measurement, also known as ideal measurement, implies the probability law in a simple way. Namely, the very requirement of minimal change of state, put in proper mathematical form, gives the well known Lueders formula, which contains the probability rule.Comment: 8 page

A quantum measure of coherence and incompatibility

The well-known two-slit interference is understood as a special relation between observable (localization at the slits) and state (being on both slits). Relation between an observable and a quantum state is investigated in the general case. It is assumed that the amount of ceherence equals that of incompatibility between observable and state. On ground of this, an argument is peresented that leads to a natural quantum measure of coherence, called "coherence or incompatibility information". Its properties are studied in detail making use of 'the mixing property of relative entropy' derived in this article. A precise relation between the measure of coherence of an observable and that of its coarsening is obtained and discussed from the intutitive point of view. Convexity of the measure is proved, and thus the fact that it is an information entity is established. A few more detailed properties of coherence information are derived with a view to investigate final-state entanglement in general repeatable measurement, and, more importantly, general bipartite entanglement in follow ups of this study.Comment: 19 GS pages; supercedes quant-ph/030921

There exist non orthogonal quantum measurements that are perfectly repeatable

We show that, contrarily to the widespread belief, in quantum mechanics repeatable measurements are not necessarily described by orthogonal projectors--the customary paradigm of "observable". Nonorthogonal repeatability, however, occurs only for infinite dimensions. We also show that when a non orthogonal repeatable measurement is performed, the measured system retains some "memory" of the number of times that the measurement has been performed.Comment: 4 pages, 1 figure, revtex4, minor change