Relativistic formulation of quantum state diffusion?

The recently reported relativistic formulation of the well-known non-relativistic quantum state diffusion is seriously mistaken. It predicts, for instance, inconsistent measurement outcomes for the same system when seen by two different inertial observers.Comment: 5 pages LaTeX, submitted to J. Phys.

Non-Markovian Open Quantum Systems: Input-Output Fields, Memory, Monitoring

Principles of monitoring non-Markovian open quantum systems are analyzed. We use the field representation of the environment (Gardiner and Collet, 1985) for the separation of its memory and detector part, respectively. We claim the system-plus-memory compound becomes Markovian, the detector part is tractable by standard Markovian monitoring. Because of non-Markovianity, only the mixed state of the system can be predicted, the pure state of the system can be retrodicted. We present the corresponding non-Markovian stochastic Schr\"odinger equation.Comment: 5 pages, 3 postscript figures; version with brief important improvement

Non-coherent successive relaying and cooperation: principles, designs, and applications

Cooperative communication is capable of forming a virtual antenna array for each node (user) in a network by allowing the nodes (users) to relay the messages of others to the destination. Such a relay aided network may be viewed as a distributed multiple-input multiple-output (MIMO) system relying on the spatially distributed single antennas of the cooperating mobiles, which avoids the correlation of the antenna elements routinely encountered in conventional MIMO systems and hence attains the maximum achievable diversity gain. Therefore, the family of cooperative communication techniques may be regarded as a potential solution for future wireless networks. However, constrained by the half-duplex transmit/receive mode of most practical transceivers, the cooperative networks may impose a severe 50% throughput loss. As a remedy, successive relaying can be employed, which is capable of mimicking a full-duplex relay and thereby recovering much of the 50% throughput loss. Furthermore, for the sake of bypassing power-hungry and potentially excessive-complexity channel estimation, noncoherent detection techniques may be employed for multiple-antenna aided systems, because estimating all the associated channels may become unrealistic. Explicitly, the mobile-stations acting as relays cannot be realistically expected to estimate the source-to-relay channels. In order to motivate further research on noncoherent successive relaying aided systems, a comprehensive review of its basic concepts, fundamental principles, practical transceiver designs and open challenges is provide

Advancement of estimation fidelity in continuous quantum measurement

We estimate an unknown qubit from the long sequence of n random polarization measurements of precision Delta. Using the standard Ito-stochastic equations of the aposteriori state in the continuous measurement limit we calculate the advancement of fidelity. We show that the standard optimum value 2/3 is achieved asymptotically for n >> Delta^2 / 96 >> 1. We append a brief derivation of novel Ito-equations for the estimate state.Comment: 12 pp LaTe

Bilocal *-automorphisms of B(H)

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Colour evolution of conventionally and organically cultivated Hungarian red spice paprika varieties

Colour evolution of conventionally and organically cultivated Szegedi-20, Meteorit, Mihálytelki and Kármin spice paprika varieties was studied in green, break, pale red, deep red and over-ripened maturity stages. As the ripening stages forwarded the organic samples gradually lost their initial extractable colour (ASTA value) gain toward their conventional counterparts. The over-ripened colour levels were satisfactorily high in the conventional (169.9-264.8 ASTA) and in the organic (160.8-210.5 ASTA) paprika varieties as well, although the colour accumulation was 9.0-62.8 ASTA lower in the organic samples. Significant and perceptible visual colour differences (ΔE*ab) were found between the organic and conventional crops. The lightness difference (ΔL*) indicated that the organic paprika generally were lighter than the conventional ones. The positive hue difference (ΔH*ab) showed that the colour of deep red and over-ripened organic Szegedi-20, Mihálytelki and Kármin paprika crops were more yellow compared with the conventional group. The lightness (L*) and hue angle (h°ab) were found the most suitable instrumental colour parameters to distinguish the ripening stages and the colour characteristics of the samples. The better colour evolution of conventional crops was attributed to the soil characteristics, nutrient supply and chemical plant protection that were specifically designed for the needs of paprika in the conventional farming

Thermal conductivity of ultrathin nano-crystalline diamond films determined by Raman thermography assisted by silicon nanowires

The thermal transport in polycrystalline diamond films near its nucleation region is still not well understood. Here, a steady-state technique to determine the thermal transport within the nano-crystalline diamond present at their nucleation site has been demonstrated. Taking advantage of silicon nanowires as surface temperature nano-sensors, and using Raman Thermography, the in-plane and cross-plane components of the thermal conductivity of ultra-thin diamond layers and their thermal barrier to the Si substrate were determined. Both components of the thermal conductivity of the nano-crystalline diamond were found to be well below the values of polycrystalline bulk diamond, with a cross-plane thermal conductivity larger than the in-plane thermal conductivity. Also a depth dependence of the lateral thermal conductivity through the diamond layer was determined. The results impact the design and integration of diamond for thermal management of AlGaN/GaN high power transistors and also show the usefulness of the nanowires as accurate nano-thermometers. (C) 2015 AIP Publishing LLC

Classical-Quantum Coexistence: a `Free Will' Test

Von Neumann's statistical theory of quantum measurement interprets the instantaneous quantum state and derives instantaneous classical variables. In realty, quantum states and classical variables coexist and can influence each other in a time-continuous way. This has been motivating investigations since longtime in quite different fields from quantum cosmology to optics as well as in foundations. Different theories (mean-field, Bohm, decoherence, dynamical collapse, continuous measurement, hybrid dynamics, e.t.c.) emerged for what I call `coexistence of classical continuum with quantum'. I apply to these theories a sort of `free will' test to distinguish `tangible' classical variables useful for causal control from useless ones.Comment: 7pp, based on talk at Conf. on Emergent Quantum Mechanics, Heinz von Foerster Congress (Vienna University, Nov 11-13, 2011