The behavior of a one-dimensional ladder when both disorder and a magnetic field are present is investigated. It is shown that the geometrical mean of its transmission probability oscillates with a strong half-flux quantum harmonic. Moreover, modification of the ladder topology shows that higher harmonics do not contribute to the oscillating behavior, which depends on the smallest closed loop available in the system. Finally, slight randomization of the flux from cell to cell causes a rapid damping of the effect in agreement with an exponential damping law of the magnetoresistance oscillation with increasing magnetic field. Conditions on the disorder necessary for the effect are briefly discussed.

• Received 3 February 1986

DOI:https://doi.org/10.1103/PhysRevB.33.6644