arXiv subjects

A. Ayari

Publications and source records attributed to A. Ayari.

3 recordsLinked to original sources

arXiv2018

Sensing and cooling of a nanomechanical resonator with an electron beam stimulated internal feedback and a capacitive force

A model for the cooling properties of a nanocantilever by a free electron beam is presented for a capacitive interaction. The optimal parameters for position sensing and cooling applications are estimated from previous experimental conditions. In particular , we demonstrate that a purely capacitive force and an electron beam stimulated internal feedback can lower the temperature of a nanocantilever by several orders of magnitude in striking contrast with the conventional electrostatic damping regime. We propose a step by step protocol to extract the interdependent parameters of the experiments. This work will aid future developments of ultra sensitive force sensors in electron microscopes.

cond-mat.mes-hall↗

arXiv2010

Simple modeling of self-oscillation in Nano-electro-mechanical systems

We present here a simple analytical model for self-oscillations in nano-electro-mechanical systems. We show that a field emission self-oscillator can be described by a lumped electrical circuit and that this approach is generalizable to other electromechanical oscillator devices. The analytical model is supported by dynamical simulations where the electrostatic parameters are obtained by finite element computations.

cond-mat.mes-hall↗

arXiv2002

Role of the dimerized gap due to anion ordering in spin-density wave phase of (TMTSF)$_2$ClO$_4$ at high magnetic fields

Magnetoresistance measurements have been carried out along the highly conducting a axis in the FISDW phase of hydrogened and deuterated (TMTSF)$_2$ClO$_4$ for various cooling rates through the anion ordering temperature. With increasing the cooling rate, a) the high field phase boundary $β_{\rm {HI}}$, observed at 27 T in hydrogened samples for slowly cooled, is shifted towards a lower field, b) the last semimetallic SDW phase below $β_{\rm {HI}}$ is suppressed, and c) the FISDW insulating phase above $β_{\rm {HI}}$ is enhanced in both salts. The cooling rate dependence of the FISDW transition and of $β_{\rm {HI}}$ in both salts can be explained by taking into account the peculiar SDW nesting vector stabilized by the dimerized gap due to anion ordering.

cond-mat.str-el↗