Quantum Hall effect in a bulk crystal

Abstract

We have observed remarkably flat Hall plateaus (step ratios . . .5:4:3:2:1) with correspondingly sharp peaks in the magnetoresistance in the Bechgaard salt (TMTSF${)}_{2}$${\mathrm{PF}}_{6}$. This highly anisotropic conductor exhibits magnetic-field-induced spin-density-wave (FISDW) states at low temperatures and pressures above about 6 kbar. Unlike previous measurements on similar materials we find almost complete confirmation of the theoretical model for the FISDW transitions, their quantum Hall effects, and the predicted high-field semiconducting state.