New field-induced spin density wave phenomena from the Pauli terms in excitonic insulators

Usually, one expects the Zeeman magnetic field to compete with a charge density wave (CDW) or a spin density wave (SDW). We report for the first time here that under quite generic conditions, the Zeeman magnetic field may induce transitions from CDW to CDW+SDW therefore generating SDW states that could not exist at zero field. Our field-induced CDW to SDW+CDW transition may provide among others, a direct explanation to puzzling for two decades findings in 2H-TaS2