Evidence for coherent interchain electron transport in quasi-one-dimensional molecular conductors

Abstract

The angular magnetoresistance of the organic superconductor (TMTSF)(2)ReO4 was measured up to 13.5 T. Exceptionally well-resolved angular magnetoresistance oscillations were observed, and analysis of these oscillations revealed several important features concerning interlayer transport. Lebed resonance dips up to the twenty-first order and subresonance dips corresponding to p/q=nonintegers were observed. The key finding of this work was that, unlike other organic conductors of the form (TMTSF)(2)X, (TMTSF)(2)ReO4 exhibits the Lebed resonance effect only when both p and q are odd integers. A simple explanation for this phenomenon, based on the unique anion ordering with wave vector (0, 1/2, 1/2), is presented. This simple model can be applied to all Bechgaard salts. The analysis shows that interchain electron transport is coherent even though chains are as far apart as 200 Angstrom or more.