Advance particle and Doppler measurement methods

Particle environments, i.e., rain, ice, and snow particles are discussed. Two types of particles addressed are: (1) the natural environment in which airplanes fly and conduct test flights; and (2) simulation environments that are encountered in ground-test facilities such as wind tunnels, ranges, etc. There are characteristics of the natural environment that one wishes to measure. The liquid water content (LWC) is the one that seems to be of most importance; size distribution may be of importance in some applications. Like snow, the shape of the particle may be an important parameter to measure. As one goes on to environment in simulated tests, additional parameters may be required such as velocity distribution, the velocity lag of the particle relative to the aerodynamic flow, and the trajectory of the particle as it goes through the aerodynamic flow and impacts on the test object

Localized quantum walks as secured quantum memory

We show that a quantum walk process can be used to construct and secure quantum memory. More precisely, we show that a localized quantum walk with temporal disorder can be engineered to store the information of a single, unknown qubit on a compact position space and faithfully recover it on demand. Since the localization occurss with a finite spread in position space, the stored information of the qubit will be naturally secured from the simple eavesdropper. Our protocol can be adopted to any quantum system for which experimental control over quantum walk dynamics can be achieved.Comment: 7 pages, 4 figure

Odd-petal states and persistent flows in spin-orbit-coupled Bose-Einstein condensates

We study the phase diagram of a Rashba spin-orbit-coupled Bose-Einstein condensate confined in a two-dimensional toroidal trap. In the immiscible regime we find an azimuthally periodic density distribution, with the periodicity highly tuneable as a function of the spin-orbit coupling strength and which favours an odd number of petals in each component. This allows for a wide range of states that can be created. We further show that in the miscible regime, both components possess states with persistent flows with a unit winding number difference between them and with the absolute values of these winding numbers depending on the spin-orbit coupling strength. All features of the odd-petal and the persistent flow states can be explained using a simple but effective model.Comment: 5 pages, 2 figure

Emergence of District-Heating Networks; Barriers and Enablers in the Development Process

Infrastructure provision business models that promise resource efficiencies and additional benefits, such as job creation, community cohesion and crime reduction exist at sub-national scales. These local business models, however, exist only as isolated cases of good practice and their expansion and wider adoption has been limited in the context of many centralised systems that are currently the norm. In this contribution, we present a conceptual agent based model for analysing the potential for different actors to implement local infrastructure provision business models. The model is based on agents’ ability to overcome barriers that occur throughout the development (i.e. feasibility, business case, procurement, and construction), and operation and maintenance of alternative business models. This presents a novel approach insofar as previous models have concentrated on the acceptance of alternative value provision models rather than the emergence of underlying business models. We implement the model for the case study of district heating networks in the UK, which have the potential to significantly contribute to carbon emission reductions, but remain under-developed compared with other European countries

Uncertainty reconciles complementarity with joint measurability

The fundamental principles of complementarity and uncertainty are shown to be related to the possibility of joint unsharp measurements of pairs of noncommuting quantum observables. A new joint measurement scheme for complementary observables is proposed. The measured observables are represented as positive operator valued measures (POVMs), whose intrinsic fuzziness parameters are found to satisfy an intriguing pay-off relation reflecting the complementarity. At the same time, this relation represents an instance of a Heisenberg uncertainty relation for measurement imprecisions. A model-independent consideration show that this uncertainty relation is logically connected with the joint measurability of the POVMs in question.Comment: 4 pages, RevTeX. Title of previous version: "Complementarity and uncertainty - entangled in joint path-interference measurements". This new version focuses on the "measurement uncertainty relation" and its role, disentangling this issue from the special context of path interference duality. See also http://www.vjquantuminfo.org (October 2003

Measurement-induced generation of spatial entanglement in a two-dimensional quantum walk with single-qubit coin

One of the proposals for the exploitation of two-dimensional quantum walks has been the efficient generation of entanglement. Unfortunately, the technological effort required for the experimental realization of standard two-dimensional quantum walks is significantly demanding. In this respect, an alternative scheme with less challenging conditions has been recently studied, particularly in terms of spatial-entanglement generation [C. Di Franco, M. Mc Gettrick, and Th. Busch, Phys. Rev. Lett. 106, 080502 (2011)]. Here, we extend the investigation to a scenario where a measurement is performed on the coin degree of freedom after the evolution, allowing a further comparison with the standard two-dimensional Grover walk.Comment: 9 pages, 4 figures, RevTeX

Quantum Mechanics as a Framework for Dealing with Uncertainty

Quantum uncertainty is described here in two guises: indeterminacy with its concomitant indeterminism of measurement outcomes, and fuzziness, or unsharpness. Both features were long seen as obstructions of experimental possibilities that were available in the realm of classical physics. The birth of quantum information science was due to the realization that such obstructions can be turned into powerful resources. Here we review how the utilization of quantum fuzziness makes room for a notion of approximate joint measurement of noncommuting observables. We also show how from a classical perspective quantum uncertainty is due to a limitation of measurability reflected in a fuzzy event structure -- all quantum events are fundamentally unsharp.Comment: Plenary Lecture, Central European Workshop on Quantum Optics, Turku 2009