Lebed resonance in quasi-one-dimensional organic conductors

We consider a strongly anisotropic three-dimensional conductor in a magnetic field perpendicular to the most conducting direction. We show that the magnetoresistance exhibits a series of resonance like dips when the magnetic field takes particular angles in the b-c plane where periodic motion in the b and the c direction becomes commensurate. The model is consistent with the initial idea of Lebed and describes recent experiments in (TMTSF)₂{ClO}₄$ (where TMTSF is tetramethyltetravelenafulvalene) quite well.