Paper detail

Thermal noise induced stochastic resonance in self organizing Fe nanoparticle system

The natural world is replete with examples of multistable systems, known to respond to periodic modulations and produce a signal, which exhibits resonance with noise amplitude. This is a concept not demonstrated in pure materials, which involve a measured physical property. In a thermoremanent magnetization experiment with a common magnetic material, Fe, in the nanoparticulate form, we establish how magnetization in a system of dilute spins during dissipation of stored magnetic energy, breaks up into spontaneous oscillatory behavior. Starting at 175 K and aided by temperature (stochastic noise) the oscillation amplitude goes through a maximum, reminiscent of stochastic resonance. Our observation of thermal noise induced coherent resonance is due to intrinsic self-organizing magnetic dynamics of the Fe nanoperticle system without applying any external periodic force. These results yield new possibilities in design of magnetic materials and a platform to understand stochastic interference and phase synchronization in neural activity, as models for neural communication.