  Bestriding the realms of classical and quantum mechanics, nanomechanical
structures offer great promise for a huge variety of applications, from
computer memory elements \cite{badzey04} and ultra-fast sensors to quantum
computing. Intriguing as these possibilities are, there still remain many
important hurdles to overcome before nanomechanical structures approach
anything close to their full potential. With their high surface-to-volume
ratios and sub-micron dimensions, nanomechanical structures are strongly
affected by processing irregularities and susceptible to nonlinear effects.
There are several ways of dealing with nonlinearity: exceptional fabrication
process control in order to minimize the onset of nonlinear effects or taking
advantage of the interesting and oftentimes counterintuitive consequences of
nonlinearity. Here, we present evidence for the use of stochastic resonance as
a means of coherent signal amplification for use in nanomechanical devices.
Aside from being simply one more system in which the phenomenon has been
demonstrated, nanoscale systems \cite{lee03} are interesting because of their
proximity to the realm of quantum mechanics. The combination of stochastic
resonance and quantum mechanics has been the subject of intense theoretical
activities \cite{wellens00, goychuk99, grif96, lof94} for many years;
nanomechanical systems present a fertile ground for the study of a broad
variety of novel phenomena in quantum stochastic resonance. Additionally, the
physical realization of such nonlinear nanomechanical strings offer the
possibility of studying a whole class of phase transition phenomena,
particularly those modeled by a Landau-Ginzburg quantum string \cite{benzi85,
hu99}.
