A fluctuation‐based probe to athermal phase transitions

We focus on athermal phase transitions where in discrete and dissipative avalanches are observed in physical observables as the system jumps from one metastable state to another, when driven by an external field. Using higher order statistics of time dependent avalanches, or noise, in electrical resistivity during temperature‐driven martensite transformation in thin nickel‐titanium films, we demonstrate evidence suggesting the existence of a singular ‘global instability’ or divergence of the correlation length as a function of temperature at the transition. These results not only establish a mapping of non‐equilibrium first order phase transition and equilibrium critical phenomena, but perhaps also call for a re‐evaluation of many existing experimental claims of self‐organized criticality.