  A single vortex in the charged Bose gas (CBG) has a charged core and its
profile different from the vortex in neutral and BCS superfluids. Lower and
upper critical fields of CBG are discussed. The unusual resistive upper
critical field, Hc2(T), of many cuprates and a few other unconventional
superconductors is described as the Bose-Einstein condensation field of
preformed bosons-bipolarons. Its nonlinear temperature dependence follows from
the scaling arguments. Exceeding the Pauli paramagnetic limit is explained.
Controversy in the determination of Hc2(T) of cuprates from kinetic and
thermodynamic measurements is addressed in the framework of the bipolaron
theory.
