We study the spectral response of a nonlinear system of coupled oscillator equations representing the overdamped two-junction (dc) superconducting quantum interference device (SQUID) loop; this system admits of static or oscillatory solutions for the autonomous case. In the presence of a weak time-dependent sinusoidal target signal and noise we find, in the regime of oscillatory or "running" solutions, an enhancement of the response (characterized by an output signal-to-noise ratio at the drive frequency) as a function of the intrinsic device parameters as well as externally controlled bias parameters that determine the nature of the long-time solutions. Modeling the device via a derived input-output transfer characteristic yields results in good agreement with recent experiments. This work offers a technique whereby the response of nonlinear devices with similar response characteristics may be optimized without directly adjusting the system noise. (C) 1999 Published by Elsevier Science B.V.

Nonlinear signal amplification in a 2D system operating in static and oscillatory regimes

GAMMAITONI, Luca
1999

Abstract

We study the spectral response of a nonlinear system of coupled oscillator equations representing the overdamped two-junction (dc) superconducting quantum interference device (SQUID) loop; this system admits of static or oscillatory solutions for the autonomous case. In the presence of a weak time-dependent sinusoidal target signal and noise we find, in the regime of oscillatory or "running" solutions, an enhancement of the response (characterized by an output signal-to-noise ratio at the drive frequency) as a function of the intrinsic device parameters as well as externally controlled bias parameters that determine the nature of the long-time solutions. Modeling the device via a derived input-output transfer characteristic yields results in good agreement with recent experiments. This work offers a technique whereby the response of nonlinear devices with similar response characteristics may be optimized without directly adjusting the system noise. (C) 1999 Published by Elsevier Science B.V.
1999
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11391/925557
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 19
  • ???jsp.display-item.citation.isi??? 19
social impact