Dissimilarity between metallic-like transport in the dielectric spin density wave and field induced spin density wave states in (TMTSF)$_2$PF$_6$

We report similarities and differences of the transport features in the spin density wave (SDW) and in the field induced SDW (FISDW) phases of the quasi one-dimensional compound (TMTSF)$_2$PF$_6$. As temperature decreases below $\approx 2$ K, the resistance in both phases exhibits a maximum and a subsequent strong drop. However, the characteristic temperature of the $R(T)$ maximum and its scaling behavior in different magnetic fields $B$ evidence that the non-monotonic $R(T)$ dependences have different origin in SDW and FISDW regions of the phase diagram. We also found that the borderline $T_0(B,P)$ which divides the FISDW region of the $P{-}B{-}T$-phase diagram into the hysteresis and non-hysteresis domains, terminates in the $N=1$ sub-phase; the borderline has thus no extension to the SDW $N=0$ phase.