Field-induced spin density wave in (TMTSF)$_2$NO$_3$
  Interlayer magnetoresistance of the Bechgaard salt (TMTSF)$_2$NO$_3$ is investigated up to 50 teslas under pressures of a few kilobars. This compound, the Fermi surface of which is quasi two-dimensional at low temperature, is a semi metal under pressure. Nevertheless, a field-induced spin density wave is evidenced at 8.5 kbar above $\sim$ 20 T. This state is characterized by a drastically different spectrum of the quantum oscillations compared to the low pressure spin density wave state. 
David Vignolles (LNCMP), Alain Audouard (LNCMP), Marc Nardone (LNCMP),   Luc Brossard (LNCMP), Sabrina Bouguessa (ENSCM), Je...