2,155 research outputs found
Characteristics of the dynamics of breakdown filaments in Al2O3/InGaAs stacks
In this paper, the Al2O3/InGaAs interface was studied by X-ray photoelectron spectroscopy (XPS) after a breakdown (BD) event at positive bias applied to the gate contact. The dynamics of the BD event were studied by comparable XPS measurements with different current compliance levels during the BD event. The overall results show that indium atoms from the substrate move towards the oxide by an electro-migration process and oxidize upon arrival following a power law dependence on the current compliance of the BD event. Such a result reveals the physical feature of the breakdown characteristics of III-V based metal-oxide-semiconductor devices.Fil: Palumbo, FĂ©lix Roberto Mario. ComisiĂłn Nacional de EnergĂa AtĂłmica; Argentina. Universidad TecnolĂłgica Nacional; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Shekhter, P.. Technion - Israel Institute of Technology; IsraelFil: Cohen Weinfeld, K.. Technion - Israel Institute of Technology; IsraelFil: Eizenberg, M.. Technion - Israel Institute of Technology; Israe
Hybrid SGP4 orbit propagator
Two-Line Elements (TLEs) continue to be the sole public source of orbiter
observations. The accuracy of TLE propagations through the Simplified General
Perturbations-4 (SGP4) software decreases dramatically as the propagation
horizon increases, and thus the period of validity of TLEs is very limited. As
a result, TLEs are gradually becoming insufficient for the growing demands of
Space Situational Awareness (SSA). We propose a technique, based on the hybrid
propagation methodology, aimed at extending TLE validity with minimal changes
to the current TLE-SGP4 system in a non-intrusive way. It requires that the
institution in possession of the osculating elements distributes hybrid TLEs,
HTLEs, which encapsulate the standard TLE and the model of its propagation
error. The validity extension can be accomplished when the end user processes
HTLEs through the hybrid SGP4 propagator, HSGP4, which comprises the standard
SGP4 and an error corrector.Comment: 18 pages, 4 figure
Guided Quasicontinuous Atom Laser
We report the first realization of a guided quasicontinuous atom laser by rf
outcoupling a Bose-Einstein condensate from a hybrid optomagnetic trap into a
horizontal atomic waveguide. This configuration allows us to cancel the
acceleration due to gravity and keep the de Broglie wavelength constant at 0.5
m during 0.1 s of propagation. We also show that our configuration,
equivalent to pigtailing an optical fiber to a (photon) semiconductor laser,
ensures an intrinsically good transverse mode matching.Comment: version published in Phys. Rev. Lett. 97, 200402 (2006
First-order sidebands in circuit QED using qubit frequency modulation
Sideband transitions have been shown to generate controllable interaction
between superconducting qubits and microwave resonators. Up to now, these
transitions have been implemented with voltage drives on the qubit or the
resonator, with the significant disadvantage that such implementations only
lead to second-order sideband transitions. Here we propose an approach to
achieve first-order sideband transitions by relying on controlled oscillations
of the qubit frequency using a flux-bias line. Not only can first-order
transitions be significantly faster, but the same technique can be employed to
implement other tunable qubit-resonator and qubit-qubit interactions. We
discuss in detail how such first-order sideband transitions can be used to
implement a high fidelity controlled-NOT operation between two transmons
coupled to the same resonator.Comment: 15 pages, 5 figure
Citation Flows in the Zones of Influence of Scientific
Domestic citation to papers from the same country and the greater citation impact of documents involving international collaboration are two phenomena that have been extensively studied and contrasted. Here, however, we showthat it is not somuch a national bias,but that papers have a greater impact on their immediate environments, an impact that is diluted as that environment grows. For this reason, the greatest biases are observed in countries
with a limited production. Papers that involve international collaboration have a greater impact in general, on the one hand, because they have multiple âimmediate
environments,â and on the other because of their greater quality or prestige. In short, one can say that science knows no frontiers. Certainly there is a greater impact
on the authorsâ immediate environment, but this does not necessarily have to coincide with their national environments, which fade in importance as the collaborative
environment expands
- âŠ