Noise anisotropy in YBa2Cu3O7-d thin films

Anisotropy of voltage noise in YBa(2)Cu(3)O(7-delta) thin films was investigated using (103)/(013) oriented films. Normalized noise in the normal state does not depend on the direction of current flow, while in the superconducting state the noise is anisotropic. The difference stems from different origins of noise. Normal state noise is due to random motion of charge carriers while in the superconducting state it arises from fluctuations of density and/or velocity of flux vortices.