Metal-phase stability of (TMTSF)2ClO4 in high magnetic fields, where TMTSF is tetramethyltetraselenafulvalene
The field-induced spin-density-wave state in (TMTSF)2ClO4, where TMTSF is tetramethyltetraselenafulvalene, develops because the field diminishes the ``antinesting'' terms, t'b, to restore the spin-density wave (SDW) that would exist at t'b=0 despite the anion gap in ClO4. The gap changes the wave function's symmetry for ``nested'' subbands-one of them changes sign upon crossing the new zone boundary, destroying the coherence of paired electrons at H≠0. Competition between the two phenomena leads to a reentrance of the metallic state. Magnetic breakdown is unable to restore a PF6-type ground state and reveals itself in a pattern of peaks for TSDW(H) periodic in H-1.