We have studied the high-field (up to H=30 T) magnetoconductivity (Δσ(H)/σ(0)=[σ(H)-σ(0)]/ σ(0)) of highly conducting polyacetylene films heavily doped with Cl4-, FeCl4-, and iodine at the temperature range 0.6-1.4 K. At relatively low fields, their field dependence is different from each other according to the specific properties of the dopant with which the spin state of conduction electrons are coupled. In the high-field region, however, the magnetoconductivity is linearly dependent on the magnetic field irrespective of the type of dopants. The change from the low field Δσ(H)/σ(0)∝H1/2 to the high field Δσ-(H)/σ-(0)∝H as well as the effect of dopants is attributed to the competition between the magnetic length LH and the dopant-specific length scales, both of which are relevant to the delocalization under the magnetic field. The origin of linear dependence of magnetoconductivity at high fields is also discussed.
|Number of pages||5|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 15 Apr 2002|