In relativistic magnetized plasmas, asymmetry in the number densities of left- and right-handed fermions, i.e., a nonzero chiral chemical potential ${\mu }_5$, leads to an electric current along the magnetic field. This causes a chiral dynamo instability for a uniform ${\mu }_5$, but our simulations reveal a dynamo even for fluctuating ${\mu }_5$ with zero mean. It produces magnetically dominated turbulence and generates mean magnetic fields via the magnetic $\alpha$ effect. Eventually, a universal scale-invariant $k^{-1}$ spectrum of ${\mu }_5$ and a $k^{-3}$ magnetic spectrum are formed independently of the initial condition.

• Received 27 July 2021
• Revised 12 November 2021
• Accepted 1 December 2021

DOI:https://doi.org/10.1103/PhysRevLett.128.065002