Strong and Weak Dynamo Regimes in Taylor-Couette Flows

We reveal a nonlinear magnetic dynamo in a Taylor-Couette flow at small magnetic Prandtl numbers Pm≤1, which has been previously believed to exist only at higher Pm≳10 in this flow. The amplitude of initial perturbations, Pm, and domain aspect ratio play a key role in the onset and evolution of the dynamo. It exists in two main states: a weak state dominated by large-scale modes and a strong, turbulent state with higher amplitude dominated by small-scale modes. These findings can be important for dynamo processes in various astrophysical objects with small Pm.