Quantum reading of digital memory with non-Gaussian entangled light

It has been shown recently (Phys. Rev. Lett. 106, 090504 (2011)) that entangled light with Einstein-Podolsky-Rosen (EPR) correlations retrieves information from digital memory better than any classical light. In identifying this, a model of digital memory with each cell consisting of reflecting medium with two reflectivities (each memory cell encoding the binary numbers 0 or 1) is employed. The readout of binary memory essentially corresponds to discrimination of two Bosonic attenuator channels characterized by different reflectivities. The model requires an entire mathematical paraphernalia of continuous variable Gaussian setting for its analysis, when arbitrary values of reflectivities are considered. Here we restrict to a basic quantum read-out mechanism with non-Gaussian entangled states of light, with the binary channels to be discriminated being ideal memory characterized by reflectivity one i.e., an identity channel and thermal noise channel, where the signal light illuminating the memory location gets completely lost (zero reflectivity) and only a white thermal noise hitting the upper side of the memory reaches the decoder. We compare the quantum reading efficiency of entangled light with any classical source of light in this model. We show that entangled transmitters offer better reading performance than any classical transmitters of light in the regime of low signal intensity.Comment: 7 pages, 6 figures, To appear in Phys. Rev.

Joint Measurability and Temporal Steering

Quintino et. al. (Phys. Rev. Lett. 113, 160402 (2014)) and Uola et. al. (Phys. Rev. Lett. 113, 160403 (2014)) have recently established an intrinsic relation between non-joint measurability and Einstein-Podolsky- Rosen steering. They showed that a set of measurements is incompatible (i.e., not jointly measurable) if and only if it can be used for the demonstration of steering. In this paper, we prove the temporal analog of this result viz., a set of measurements are incompatible if and only if it exhibits temporal steering.Comment: 6 pages,no figures, typos corrected, improved presentation; To appear in JOSA B feature issue "80 years of Steering and the Einstein-Podolsky-Rosen Paradox

Radio and infrared study of the star forming region IRAS 20286+4105

A multi-wavelength investigation of the star forming complex IRAS 20286+4105, located in the Cygnus-X region, is presented here. Near-infrared K-band data is used to revisit the cluster / stellar group identified in previous studies. The radio continuum observations, at 610 and 1280 MHz show the presence of a HII region possibly powered by a star of spectral type B0 - B0.5. The cometary morphology of the ionized region is explained by invoking the bow-shock model where the likely association with a nearby supernova remnant is also explored. A compact radio knot with non-thermal spectral index is detected towards the centre of the cloud. Mid-infrared data from the Spitzer Legacy Survey of the Cygnus-X region show the presence of six Class I YSOs inside the cloud. Thermal dust emission in this complex is modelled using Herschel far-infrared data to generate dust temperature and column density maps. Herschel images also show the presence of two clumps in this region, the masses of which are estimated to be {\sim} 175 M{\sun} and 30 M{\sun}. The mass-radius relation and the surface density of the clumps do not qualify them as massive star forming sites. An overall picture of a runaway star ionizing the cloud and a triggered population of intermediate-mass, Class I sources located toward the cloud centre emerges from this multiwavelength study. Variation in the dust emissivity spectral index is shown to exist in this region and is seen to have an inverse relation with the dust temperature.Comment: 20 pages, 16 figures, accepted for publication in MNRA

Building Relationships between Business Schools and Students: An Empirical Investigation into Student Retention

This study uses the relationship marketing theory of commitment and trust as a framework to investigate the issue of student retention in business schools. Structural equation modeling was used to examine relationships specified by Morgan and Hunt\u27s (1994) theory of relationship marketing. Students\u27 commitment to the business schools were determined by perceived benefits of attending the school, perceived similarity of values between the school and the students, and trust between the professors and the students. Commitment increased intentions to remain at the business school

Building Relationships Between Business Schools And Students: An Empirical Investigation Into Student Retention

This study uses the relationship marketing theory of commitment and trust as a framework to investigate the issue of student retention in business schools. Structural equation modeling was used to examine relationships specified by Morgan and Hunt's (1994) theory of relationship marketing.  Students' commitment to the business schools were determined by perceived benefits of attending the school, perceived similarity of values between the school and the students, and trust between the professors and the students.  Commitment increased intentions to remain at the business school

Transferring structural knowledge across cognitive maps in humans and models

Relations between task elements often follow hidden underlying structural forms such as periodicities or hierarchies, whose inferences fosters performance. However, transferring structural knowledge to novel environments requires flexible representations that are generalizable over particularities of the current environment, such as its stimuli and size. We suggest that humans represent structural forms as abstract basis sets and that in novel tasks, the structural form is inferred and the relevant basis set is transferred. Using a computational model, we show that such representation allows inference of the underlying structural form, important task states, effective behavioural policies and the existence of unobserved state-trajectories. In two experiments, participants learned three abstract graphs during two successive days. We tested how structural knowledge acquired on Day-1 affected Day-2 performance. In line with our model, participants who had a correct structural prior were able to infer the existence of unobserved state-trajectories and appropriate behavioural policies

Deformation of lamellar TiAl alloys by longitudinal twinning

© 2016 Elsevier Ltd. The occurrence of longitudinal twinning in the engineering alloy Ti-45Al-2Nb-2Mn (at.%)-0.8 vol.% TiB2 has been studied by measuring the changes in crystallographic orientation within individual lamellae during microcompression. Twinning in this alloy appeared to be a nucleation-limited process with the twins growing from lamellar boundaries at resolved shear stresses as low as 100 MPa, consistent with observations elsewhere. However, instead of forming twins ∼ 10-200 nm in thickness, as in polysynthetically twinned crystals, the longitudinal twins in this alloy were initiated at a lamellar boundary and then spread through the whole lamella.The work was supported by the EPSRC / Rolls-Royce Strategic Partnership (EP/H500375/1). Alberto Palomares Garcia, Claire Davis and Robert Jones are acknowledged for discussions and help with the TEM respectively