New SDW and FISDW phases in quasi-one-dimensional metals with dimerization in low-conducting direction

We study the spin-density-wave (SDW) instabilities in the quasi-one-dimensional metal (TMTSF)2ClO4 within the framework of matrix RPA for intra- and inter-band order parameters. Depending on the dimerizing potential V, two SDW orders are possible. Generally, at low V the system prefers inter- band order SDW0. At high V instability toward the intra-band SDW± dominates. For intermeiate V, of order of electron inter-chain hopping t, and zero magnetic field metallic state persists down to T=0. Putting the system in magnetic field both SDW0 and SDW± are restored and compete. In particular, for V/t<0.9 a field induced first order transition from SDW0 to SDW± takes place. For V/t>0.9 only SDW± is accessible from metallic phase.