Interference effects due to commensurate electron trajectories and topological crossovers in (TMTSF )2 ClO4

We report angle-dependent magnetoresistance measurements on (TMTSF)₂ClO₄ that provide strong support for a macroscopic quantum phenomenon, the “interference commensurate” (IC) effect, in quasi-one dimensional metals. In addition to observing rich magnetoresistance oscillations, and fitting them with one-electron calculations, we observe a clear demarcation of field-dependent behavior at local resistance minima and maxima (versus field angle). Anticipated by a theoretical treatment of the IC effect in terms of Bragg reflections in the extended Brillouin zone, this behavior results from one-dimensional → two dimensional (1D→2D) topological crossovers of electron wave functions as a function of field orientation.