The analysis of nonclassical rotational response of superfluids and superconductors was performed by Onsager (in 1949) cite{Onsager} and London (in 1950) cite{London} and crucially advanced by Feynman (in 1955) cite{Feynman}. It was established that,
in thermodynamic limit, neutral superfluids rotate by forming---without any threshold---a vortex lattice. In contrast, the rotation of superconductors at angular frequency ${bf Omega}$---supported by uniform magnetic field ${bf B}_Lpropto {bf Omega}$ due to surface currents---is of the rigid-body type (London Law). Here we show that, neglecting the centrifugal effects, the behavior of a rotating superconductor is identical to that of a superconductor placed in a uniform fictitious external magnetic filed $tilde{bf H}=- {bf B}_L$. In particular, the isomorphism immediately implies the existence of two critical rotational frequencies in type-2 superconductors.
