Entanglement, non-Markovianity, and causal non-separability

Quantum mechanics, in principle, allows for processes with indefinite causal order. However, most of these causal anomalies have not yet been detected experimentally. We show that every such process can be simulated experimentally by means of non-Markovian dynamics with a measurement on additional degrees of freedom. Explicitly, we provide a constructive scheme to implement arbitrary acausal processes. Furthermore, we give necessary and sufficient conditions for open system dynamics with measurement to yield processes that respect causality locally, and find that tripartite entanglement and nonlocal unitary transformations are crucial requirements for the simulation of causally indefinite processes. These results show a direct connection between three counter-intuitive concepts: non-Markovianity, entanglement, and causal indefiniteness.Comment: 14 pages, 8 figure

Spin-chain model of a many-body quantum battery

Recently, it has been shown that energy can be deposited on a collection of quantum systems at a rate that scales super-extensively. Some of these schemes for `quantum batteries' rely on the use of global many-body interactions that take the batteries through a correlated short cut in state space. Here, we extend the notion of a quantum battery from a collection of a priori isolated systems to a many-body quantum system with intrinsic interactions. Specifically, we consider a one-dimensional spin chain with physically realistic two-body interactions. We find that the spin-spin interactions can yield an advantage in charging power over the non-interacting case, and we demonstrate that this advantage can grow super-extensively when the interactions are long ranged. However, we show that, unlike in previous work, this advantage is a mean-field interaction effect that does not involve correlations and that relies on the interactions being intrinsic to the battery.Comment: 9 pages, 6 figure

'Another Country, Another World': English drama, 1371-1558 and the development of the English Reformation

The purpose of this dissertation is twofold. First I will show the sources of some of the dramatic changes throughout the late fifteenth and the early sixteenth century and track them through this period of religious and civic turmoil as England goes from Catholic to Protestant and back again in the space of a generation. Second, I shall demonstrate the value of directly comparing medieval texts with Tudor interludes and even later plays, placing each of them in a broader dramatic tradition relative to one another. In short, by examining texts from roughly the period of the English Reformation from its Lollard beginnings to full-fledged Protestantism under Elizabeth, I will make some suggestions as to how and why both changes and continuities in drama throughout these two centuries came about

Evaluation of a rare case of orbital venous varix with multiple intracranial venous malformations using prone MRI technique

Orbit is a common site for vascular lesions in all age groups, with venous malformations being the most common type. Orbital varices are a rare subset of venous malformation which is a vascular hamartoma that communicate with normal orbital veins. The mainstay of diagnosis and differentiation from other vascular and neoplastic lesions of orbit is demonstration of change in size of lesion on dynamic maneuvers. In this article, we present a case of left orbital venous varix which showed enlargement on Valsalva maneuver. The patient was evaluated using prone MRI technique to demonstrate increase in the size of lesion. Multiple asymptomatic developmental venous anomalies were detected on brain screening, which is a known association

The Top Ten List of Gravitational Lens Candidates from the HST Medium Deep Survey

A total of 10 good candidates for gravitational lensing have been discovered in the WFPC2 images from the HST Medium Deep Survey (MDS) and archival primary observations. These candidate lenses are unique HST discoveries, i.e. they are faint systems with sub-arcsecond separations between the lensing objects and the lensed source images. Most of them are difficult objects for ground-based spectroscopic confirmation or for measurement of the lens and source redshifts. Seven are ``strong lens'' candidates which appear to have multiple images of the source. Three are cases where the single image of the source galaxy has been significantly distorted into an arc. The first two quadruply lensed candidates were reported in Ratnatunga et al 1995 (ApJL, 453, L5) We report on the subsequent eight candidates and describe them with simple models based on the assumption of singular isothermal potentials. Residuals from the simple models for some of the candidates indicate that a more complex model for the potential will probably be required to explain the full structural detail of the observations once they are confirmed to be lenses. We also discuss the effective survey area which was searched for these candidate lens objects.Comment: 26 pages including 12 figures and 10 tables. AJ Vol. 117, No.

Lithium insertion into titanium dioxide (anatase) electrodes: Microstructure and electrolyte effects

Insertion characteristics of anatase electrodes were studied on single-crystal and polycrystalline electrodes of different microstructures. The lithium incorporation from propylene carbonate solution containing LiClO4 and Li(CF3SO2)2N was studied by means of cyclic voltammetry (CV), the quartz crystal microbalance (QCM) and the galvanostatic intermittent titration technique (GITT). The electrode microstructure affects both the accessible coefficient x and the reversibility of the process. The highest insertion activity was observed for electrodes composed of crystals with characteristic dimensions of ∼10-8 m. The insertion properties deteriorate for higher as well as for smaller crystal sizes. Enhanced insertion was observed in Li(CF3SO2)2N-containing solutions. Lithium insertion is satisfactorily reversible for mesoscopic electrodes; the reversibility in the case of compact polycrystalline and single-crystal electrodes is poor. The reversibility of the insertion improves with increasing electrolyte concentration. The lithium diffusion coefficient decreases with increasing x and ranges between 10-15 and 10-18 cm2 s-1. © Springer-Verlag 2001

Lithium insertion into mesoscopic and single-crystal TiO2 (rutile) electrodes

Electrochemical behavior of single-crystal and mesoscopic TiO2 (rutile) was studied in propylene carbonate solutions at potentials negative to the flatband potential. In electrolytic solutions containing sodium or tetrabutylammonium (Bu4N+), the injected charge is compensated by protonization of the surface and/or by adsorption of cations in the double layer. In electrolytic solutions containing Li+, the insertion into the rutile lattice occurs at potentials below 1.5 V (Li/Li+). At higher potentials, the charge is compensated mainly by a nonfaradaic process. Lithium insertion into rutile proceeds at a potential ca. 0.4 V more negative than the insertion potential into anatase. The maximum insertion capacity of rutile is also lower than that of anatase. The insertion of lithium into rutile is accompanied by an increase of the electrode mass, while the mass/charge relations show hystereses between anodic and cathodic potential sweeps. This behavior is explained in terms of a free convection in the electrode vicinity

Insertion of lithium into mesoscopic anatase electrodes - An electrochemical and in-situ EQCM study

The insertion of Li+ into mesoscopic TiO2 (anatase) electrodes was studied using cyclic voltammetry combined with the in situ gravimetric monitoring of the electrode mass in LiClO4 and Li(CF3SO2)2 N/propylene carbonate (PC)-based solutions. The insertion of Li+ takes place at potentials less than 2.0 V vs Li/Li+. The cathodic process is associated with a mass uptake; the subsequent oxidation process is associated with a mass decrease. The apparent molar mass of the inserted/extracted material is, however, remarkably different from that expected for the simple insertion/extraction of unsolvated Li+ ions. For a more accurate description of the behaviour of the mesoscopic anatase electrodes, we consider them as gold electrodes modified with a porous film. Thus, the mesoscopic anatase electrode behaves similarly to a polymer-modified electrode, i.e. the overall process includes coupled electron/ion transfer (insertion of Li+) and a transfer of neutral species. Analysing the EQCM (electrochemical quartz crystal microbalance) data, one can conclude that the controlling step of the insertion/extraction of Li+ into/from anatase electrodes is a coupled electron/ ion transfer or the transfer of neutral species in solutions containing ClO4 - and (CF3SO2)2N- respectively