New Magneto-Roton Modes in the "Ribault Phase" of the Ultra Quantum Crystal

The Ultra Quantum Crystal phases observed in quasi-one-dimensional conductors of the Bechgaard salts family under magnetic field exhibit both Spin Density Wave order and a Quantized Hall Effect. As a result, they also possess a Magneto-Roton mode within the single particle gap, and the usual Goldstone modes. The sign reversals of the Quantum Hall Effect have recently been explained within the Quantized Nesting Model. I show here that the sign reversed phases of the Ultra Quantum Crystal (the "Ribault Phases") have novel properties compared to the majority sign phases. They exhibit at least two Magneto-Roton modes, the energy of which, relative to the single particle gap, vary linearly with the magnetic field, with opposite signs, in contrast to the field dependence in the majority sign phases