## What is the Stochastic Resonance (SR) ?

- Amplification of feeble input by assistance of stochastic noise.
- Basic ingredients:
- Energetic activation barrier
- Weak coherent input (periodic signal)
- Source of noises

- Schematic example below: a particle in a double well potential with external periodic coupling
- Low T: the particle stays in one of two ground states since thermal activation is too
weak to overcome the energy barrier
- High T: hopping to other states randomly
- Intermediate T: Stochastic resonance (the hopping has the same frequency as the
external driving).

- Stochastic Resonance in Fully-Frurstrated XY Model