Hall-conductivity sign change and fluctuations in amorphous NbₓGe₁₋ₓ films

الأصل · EN

The sign change in the Hall conductivity has been studied in thin amorphous Nb₁₋ₓGeₓ (x≈0.3) films. By changing the film thickness it is shown that the field at which the sign reversal occurs shifts to lower values (from above to below the mean-field transition field Hc₂) with increasing film thickness. This effect can be understood in terms of a competition between a positive normal and a negative fluctuation contribution to the Hall conductivity.