Physics, Topology, Logic and Computation: A Rosetta Stone

In physics, Feynman diagrams are used to reason about quantum processes. In the 1980s, it became clear that underlying these diagrams is a powerful analogy between quantum physics and topology: namely, a linear operator behaves very much like a "cobordism". Similar diagrams can be used to reason about logic, where they represent proofs, and computation, where they represent programs. With the rise of interest in quantum cryptography and quantum computation, it became clear that there is extensive network of analogies between physics, topology, logic and computation. In this expository paper, we make some of these analogies precise using the concept of "closed symmetric monoidal category". We assume no prior knowledge of category theory, proof theory or computer science.Comment: 73 pages, 8 encapsulated postscript figure

Explaining Away A Model of Affective Adaptation

We propose a model of affective adaptation, the processes whereby affective responses weaken after one or more exposures to emotional events. Drawing on previous research, our approach, represented by the acronym AREA, holds that people attend to self-relevant, unexplained events, react emotionally to these events, explain or reach an understanding of the events, and thereby adapt to the events (i.e., they attend less and have weaker emotional reactions to them). We report tests of new predictions about people's reactions to pleasurable events and discuss the implications of the model for how people cope with negative events, experience emotion in different cultures, and other topics.Psycholog

Interdiffusion at Sb/Ge interfaces induced in thin multilayer films by nanosecond laser irradiation

Thin films consisting of 3 or 4 Sb and Ge alternating layers are irradiated with single nanosecond laser pulses (12 ns, 193 nm). Real time reflectivity (RTR) measurements are performed during irradiation, and Rutherford backscattering spectrometry (RBS) is used to obtain the concentration depth profiles before and after irradiation. Interdiffusion of the elements takes place at the layer interfaces within the liquid phase. The reflectivity transients allow to determine the laser energy thresholds both to induce and to saturate the process being both thresholds dependent on the multilayer configuration. It is found that the energy threshold to initiate the process is lower when Sb is at the surface while the saturation is reached at lower energy densities in those configurations with thinner layers

'Pick any' measures contaminate brand image studies

Brand image measures using the typical pick-any answer format have been shown to be unstable (Rungie et al., 2005). In the present study, we find that the poor stability results are mainly caused by the pick-any measure itself because it allows consumers to evade reporting true associations. Using a forced-choice binary measure, we find that stable brand attribute associations are in fact present with much higher incidence (70%), thus outperforming both the measures predominantly used in industry (pick-any, 41%) and academia (7-point scale measure, 59%). Under simulated optimal conditions the forced-choice binary measure leads to 90% stability of brand-attribute associations and is therefore recommended as the optimal answer format for brand image studies

Investigation of Hydrogen and Nitrogen Thermal Stability in PECVD a-Sin_x:H.

ABSTRACTWe study the high temperature (≤1300°C) thermal evolution from hydrogenated amorphous silicon nitride (a-SiNx:H) films prepared by plasma enhanced chemical vapor deposition. Two principle peaks are found, one at 525–750°C associated with hydrogen release, and one at ≥950°C from hydrogen and nitrogen release. In nitrogen-rich films (x&gt;4/3), the low temperature (525°C) peak intensity is smaller compared to silicon-rich films (x≤4/3), implying that hydrogen is more thermally stable in N-rich films. Helium dilution during film growth further reduces the low temperature peak intensity, producing the most thermally stable N-rich material, with the onset of hydrogen evolution occurring at ∼600°C. For a nitrogen-rich film, high temperature hydrogen evolution began at ∼900°C and was accompanied by nitrogen evolution starting at ∼950°C. UV-illumination of N-rich samples prior to thermal evolution produced no observable changes in the evolution spectra.</jats:p

The Relation Between Microstructure and Electronic Properties of Magnetron Sputtered a-Si_1−x,C_x:H

We have grown a-Si1-x,Cx:H films by reactive magnetron sputtering, varying the H2 partial pressure from 0 to 6 mTorr and maintaining the substrate temperature at 275°C and argon and methane partial pressures at 1.70 and 0.10 mTorr, respectively.We investigate the correlation between electronic properties and the fraction of H bonded in "microstructure," defined by the ratio of SiHx stretching mode absorptions in IR and the low temperature H2release in thermal evolution. Our results on sputtered films disprove the monotonic decrease in carrier transport with increasing microstructure fraction which is commonly observed for a-Si1-xCx:H grown by glow discharge of SiH4 and CH4. We find that the electronic properties and microstructure depend on film composition and growth technique, and that the electronic properties are not uniquely determined by the microstructure of hydrogen bonding.</jats:p

Correlation of Rutherford Backscattering and Electrical Measurements on Si Implanted InP Following Rapid Thermal and Furnace Annealing

ABSTRACTWe report on the structural and electrical properties of (100) InP resulting from the implantation of 180 keV Si+ and subsequent annealing. The radiation damage produced by implantation at substrate temperatures from 77 to 480 K is evaluated using MeV He ion channeling. Varying degrees of recrystallization are found depending on the implant temperature and choice of furnace vs. rapid thermal annealing. Samples implanted at 25°C to a dose of 3.3.1014ions/cm2 continue to display structural disorder regardless of annealing procedures. In contrast, implantation at 200°C to 3.3-1014ions/cm2 produces a low but measurable damage level. Further annealing lowered the disorder to a level similar to that of unimplanted material.The electrical activation of both low and high fluence ion doses is nearly the same at the optimal conditions for rapid thermal annealing (RTA) or furnace annealing (FA). However the electron mobility is found to be higher after hot implantation and RTA. The electrical profile after hot implantation is wider than the profile after RT implants and FA.</jats:p

Nanoscale order and crystallization in nitrogen alloyed amorphous GeTe

The nanoscale order in amorphous GeTe thin films is measured using fluctuation transmission electron microscopy FTEM . The order increases upon annealing at 145 C, which indicates a coarsening of subcritical nuclei. This correlates with a reduction in the nucleation delay time in laser crystallization. A shift in the FTEM peak positions may indicate a transformation in local bonding. In samples alloyed with 12 at. nitrogen, the order does not change upon annealing, the peak does not shift, and the nucleation time is longer. The FTEM data indicate that nitrogen suppresses the structural evolution necessary for the nucleation process and increases the thermal stability of the material. VC 2014 AIP Publishing LL