The High Magnetic Field Phase Diagram of a Quasi-One Dimensional Metal

We present a unique high magnetic field phase of the quasi-one dimensional organic conductor (TMTSF)2ClO4. This phase, termed ”Q-ClO4”, is obtained by rapid thermal quenching to avoid ordering of the ClO4 anion. The magnetic field dependent phase of Q-ClO4 is distinctly different from that in the extensively studied annealed material. Q-ClO4 exhibits a spin density wave (SDW) transition at � 5 K which is strongly magnetic field dependent. This dependence is well described by the theoretical treatment of Bjelis and Maki. We show that Q-ClO4 provides a new B-T phase diagram in the hierarchy of low-dimensional organic metals (one-dimensional towards two-dimensional), and describe the temperature dependence of the of the quantum oscillations observed in the SDW phase.