324 research outputs found
FunTAL: Reasonably Mixing a Functional Language with Assembly
We present FunTAL, the first multi-language system to formalize safe
interoperability between a high-level functional language and low-level
assembly code while supporting compositional reasoning about the mix. A central
challenge in developing such a multi-language is bridging the gap between
assembly, which is staged into jumps to continuations, and high-level code,
where subterms return a result. We present a compositional stack-based typed
assembly language that supports components, comprised of one or more basic
blocks, that may be embedded in high-level contexts. We also present a logical
relation for FunTAL that supports reasoning about equivalence of high-level
components and their assembly replacements, mixed-language programs with
callbacks between languages, and assembly components comprised of different
numbers of basic blocks.Comment: 15 pages; implementation at https://dbp.io/artifacts/funtal/;
published in PLDI '17, Proceedings of the 38th ACM SIGPLAN Conference on
Programming Language Design and Implementation, June 18 - 23, 2017,
Barcelona, Spai
Defect configurations of high-<i>k</i> cations in germanium
At germanium/high-k interfaces cations and oxygen interstitials can diffuse into the germanium substrate. Here we employ density functional theory calculations to investigate the interaction of a range of such cations (Al, Y, Zr, Nb, La, and Hf) with intrinsic defects and oxygen in germanium. It is predicted that high-k cations strongly bind with lattice vacancies, oxygen interstitials, and A-centers. The implications for microelectronic device performance are discussed. (C) 2012 American Institute of Physics
Electron density effects in the modulation spectroscopy of strained and lattice-matched InGaAs/InAlAs/InP high-electron-mobility transistor structures
The effects of the channel electron density on the interband optical transitions of strained (x=0.6 and 0.65) and lattice-matched (x=0.53) InxGa1–xAs/In0.52Al0.48As/InP high-electron-mobility transistor structures have been investigated by phototransmittance at room temperature. Analysis of the ground and first excited transitions for low and high densities, respectively, enabled a separate estimation of the electron densities occupying each one of the first two subbands. It was found necessary to include the modulation of the phase-space filling in the analysis of the spectra, especially for the samples with a high electron density, in which case this modulation mechanism becomes dominant
Electric‐field dependence of interband transitions in In_(0.53)Ga_(0.47)As/In_(0.52)Al_(0.48)As single quantum wells by room‐temperature electrotransmittance
Room‐temperature electrotransmittance has been used in order to investigate the interband excitonic transitions in a 250‐Å‐thick In_(0.53)Ga_(0.47)As/In_(0.52)Al_(0.48)As single‐quantum‐well system as a function of an externally applied electric field. Parity forbidden transitions, involving conduction‐band states with quantum numbers up to n=5, which become more pronounced at high electric fields were observed. The ground‐state and the forbidden transitions showed a significant red shift due to the quantum confined Stark effect. A comparison with previously reported results on thinner InGaAs/InAlAs quantum wells indicated that the wide‐well sample exhibits the largest shift, as expected from theory. Despite the appreciable Stark shift, the rather large, field‐induced linewidth broadening and the relatively low electric field at which the ground‐state exciton is ionized poses limitations on using this wide‐quantum‐well system for electro‐optic applications
Gate Stack Dielectric Degradation of Rare-Earth Oxides Grown on High Mobility Ge Substrates
We report on the dielectric degradation of Rare-Earth Oxides (REOs), when
used as interfacial buffer layers together with HfO2 high-k films (REOs/HfO2)
on high mobility Ge substrates. Metal-Oxide-Semiconductor (MOS) devices with
these stacks,show dissimilar charge trapping phenomena under varying levels of
Constant- Voltage-Stress (CVS) conditions, which also influences the measured
densities of the interface (Nit) and border (NBT) traps. In the present study
we also report on C-Vg hysteresis curves related to Nit and NBT. We also
propose a new model based on Maxwell-Wagner instabilities mechanism that
explains the dielectric degradations (current decay transient behavior) of the
gate stack devices grown on high mobility substrates under CVS bias from low to
higher fields, and which is unlike to those used for other MOS devices.
Finally, the time dependent degradation of the corresponding devices revealed
an initial current decay due to relaxation, followed by charge trapping and
generation of stress-induced leakage which eventually lead to hard breakdown
after long CVS stressing.Comment: 19pages (double space), 7 figures, original research article,
Submitted to JAP (AIP
Class and Politics in the Greek Debt Crisis
The mainstream view on the causes of the Eurozone crisis is that it is a fiscal crisis that emanated partly from the incompetence of the peripheral EU states to collect taxes, partly from their own states’ profligacy with a huge and uneconomic public sector, and partly from the ‘fact’ that these societies are not working as hard as their northern neighbours. This mainstream view has been defeated by original work carried out in the past few years not only by Marxisant scholars and heterodox economists, but also by important financial commentators and journalists, such as Martin Wolf of the Financial Times. The Eurozone crisis, this winning approach argued, is a balance of payments crisis that is bound up with Germany’s anti-inflationary, low wage, export-led growth creating permanent surpluses for itself and permanent deficits for the periphery. This chapter aims at going a step further. Following a ‘global fault-lines’ approach1, it produces a historical reading of the Greek social and political economy, bringing into context not just economic indicators but also geopolitical and security ones. Thus, readers will become aware that periphery social formations, especially Greece, are connected with some inextricable historical and structural contradictions and fault-lines that go well beyond the country’s entry into the EMU in 2001 and refer to the country’s geostrategic and geopolitical location in the Eastern Mediterranean and the Balkan
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