The duality that relates magnetic noise to electric shot noise

Statistical treatment of the succession in time of the Barkhausen-noise pulses shows that magnetic noise possesses characteristics that are similar to those of electric shot noise. On the other hand, the electric shot-noise intensity in a noisy component is known to be related directly to the square root of the dc current through the component. Hence, it is intriguing to relate in the same manner the magnetic-noise flux-fluctuations to a magnetic entity similar to the dc current in the electric case. The present work is a successful attempt to demonstrate that such relationship exists. This is attained by employing the duality that relates the time-derivative of the magnetic flux to the electric current. The magnetic noise measurements of commercially available thin-film magnetoresistors confirm the applicability of the proposed approach. The noise was generated by exciting the magnetoresistors by an ac magnetic field along their easy axes. The level of the resulted flux time-derivative was changed by varying the excitation frequency