Spin-density wave ground state in the one-dimensional conductor (TMTSF) 2PF6: microscopic evidence from 77Se and 1H NMR experiments

The vanishing of the 77Se nuclear resonance signal and the broadening by internal magnetic fields of the proton resonance line establish the existence of spin-density waves in the low temperature semiconducting state of (TMTSF) 2PF6. The thermally activated collective mode of the commensurate spin-density wave contributes significantly to the proton spin-lattice relaxation. It is also suggested that the very small amplitude of the spin-density wave is due to the coexistence of two diverging channels in the conducting state : the SDW and Superconductivity channels.