Change of the effective fluctuation dimensionality in vanadium thin films in a magnetic field

Lowering of the effective fluctuation dimensionality in the critical region has been found for thin superconducting vanadium films placed in strong perpensicular magnetic fields. The effect shows itself as a change of the critical index characterizing the temperature dependence of the excess film conductivity. By varying the magnetic field, one can observe both two-dimensional and zero-dimensional critical fluctuations on the same specimens.