Super-Crystalline CDW Phase in Organic Conductor (Per)$_2$Pt(mnt)$_2$*

We suggest a model [1,2], where phase transitions between the Peierls and Super-Crystalline [or soliton wall superlattice (SWS)] charge-density-wave (CDW) phases occur in a magnetic field. The model accounts for peculiarities of an electron spectrum in a quasi-one-dimensional (Q1D) conductor (Per)$_2$Pt (mnt)$_2$ . In particular, we show that the Pauli spin- splitting effects improve the nesting properties of a realistic Q1D electron spectrum, and, therefore, a high resistance Peierls CDW phase is stabilized in high magnetic fields. In low and very high magnetic fields, a periodic SWS (or Super- Crystalline) phase is found to be a ground state. We discuss [3] possible experimental investigations of the theoretically predicted phase transitions in (Per)$_2$Pt(mnt)$_2$ to discover a unique SWS phase.\newline \newline [1] A.G. Lebed and Si Wu, Phys. Rev. Lett. 99, 026402 (2007). \newline [2] A.G. Lebed and Si Wu, JETP Lett. 86, 135 (2007). \newline [3] Si Wu and A.G. Lebed, Phys. Rev. B, submitted (2008).