arXiv subjects

O. Usmani

Publications and source records attributed to O. Usmani.

4 recordsLinked to original sources

arXiv2008

Mechanical feedback in the high-frequency limit

We investigate strong mechanical feedback for the single-electron tunneling device coupled to an underdamped harmonic oscillator in the high-frequency case, when the mechanical energy of the oscillator exceeds the tunnel rate, and for weak coupling. In the strong feedback regime, the mechanical oscillations oscillated by the telegraph signal from the SET in their turn modify the electric current. In contrast to the earlier results for the low frequencies, the current noise in not enhanced above the Poisson value.

cond-mat.mes-hall↗

arXiv2006

Strong feedback and current noise in nanoelectromechanical systems

We demonstrate the feasibility of a strong feedback regime for a single-electron tunneling device weakly coupled to an underdamped single-mode oscillator. In this regime, mechanical oscillations are generated and the current is strongly modified whereas the current noise is parametrically big with respect to the Poisson value. This regime requires energy dependence of the tunnel amplitudes. For sufficiently fast tunnel rates the mechanical contribution to current noise can exceed the Poisson value even beyond the strong feedback regime.

cond-mat.mes-hall↗

arXiv2004

Single-electron Tunneling with Strong Mechanical Feedback

We show that there is a regime of strong feedback for a nanomechanical oscillatory mode weakly coupled to a single-electron tunneling device. In this regime, the current is strongly modified whereas the current noise is parametrically big exceeding the Schottky limit by orders of magnitude. This regime requires a high quality factor of nanomechanical oscillations.

cond-mat.mes-hall↗

arXiv2002

Noise-assisted classical adiabatic pumping in a symmetric periodic potential

We consider a classical overdamped Brownian particle moving in a symmetric periodic potential. We show that a net particle flow can be produced by adiabatically changing two external periodic potentials with a spatial and a temporal phase difference. The classical pumped current is found to be independent of the friction and to vanish both in the limit of low and high temperature. Below a critical temperature, adiabatic pumping appears to be more efficient than transport due to a constant external force.

cond-mat.stat-mech↗