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Your search keyword '"T. Guillet"' showing total 2 results
Start Over Author "T. Guillet" Publisher edp sciences
2 results on '"T. Guillet"'

1. Critical density for the stability of a 2D magnet array

Author

F. Bastit, D. Sulem, T. Guillet, Corentin Reiss, L. Cousin, A. Bacot, and P. Goux

Subjects
Surface (mathematics), Physics, Gravity (chemistry), Condensed matter physics, lcsh:Mathematics, Collapse (topology), lcsh:QA1-939, Stability (probability), lcsh:QC1-999, Mechanism (engineering), Magnet, Torque, Area density, lcsh:Physics
Abstract

Confining a given number of magnets with vertically aligned moments on a non-magnetic surface creates a 2D magnet array, self-organized by repulsive forces in a hexagonal crystal-like network. Increasing areal density leads to a dramatic collapse of the structure where magnets finally stick together. We study the origin of this collapse and its critical density both experimentally, by either increasing the number of magnets or reducing the area, and theoretically, by using a dipole model. We suggest the collapse occurs when magnetic forces or torques created by irregularities overcome gravity. Transition from torque-driven to force-induced mechanism is observed when the critical density increases.

Published
2018
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2. Contribution of long lived metastable states to the PL of InP dots in indirect band-gap barrier layers.

Author

R. Seguin, T. Guillet, T. Taliercio, P. Lefebvre, T. Bretagnon, X. Zhang, J. Ryou, and R. Dupuis

Abstract

We report continuous wave and time resolved photoluminescence studies of self-assembled InP quantum dots grown by metalorganic chemical vapor deposition. The quantum dots are embedded into indirect band-gap In0.5Al0.5P layers or In0.5Al0.3Ga0.2P layers with a conduction band line-up close to the direct-to-indirect crossover. As revealed by photoluminescence spectra, efficient interdiffusion of species from the barrier layers produces (Al,In)P or (Al,Ga,In)P-dots. This interdiffusion creates potential barriers that are repulsive for electrons of X valleys around the QDs. Both samples show a fast exponential decay component with a time constant between 0.5 and 0.7?ns. In addition, the sample with indirect band gap matrix shows a slow non-exponential time-decay, which is still visible after more than 100??s. The fast component is attributed to direct recombination of electron-hole pairs in the dots whilst the slow component, which follows a power law t-0.75results from recombination of holes in the dots and electrons in metastable states around the dots. [ABSTRACT FROM AUTHOR]

Published
2007
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