Magneto-rotons in the “Ribault phase” of salts
Departamento de Física, PUC-Rio, CP 38071, Rio de Janeiro,
Instituto de Física, Universidade Federal do Rio de Janeiro,
CP 68528, Rio de Janeiro, Brazil
Accepted: 7 May 1998
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 Magneto-Roton modes within the single-particle gap, and the usual Goldstone modes. 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 Magneto-Roton modes, at different wave vectors, the energy of which is significantly larger, and 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.
PACS: 72.15.Nj – Collective modes (e.g., in one-dimensional conductors) / 73.40.Hm – Quantum Hall effect (integer and fractional) / 75.30.Fv – Spin-density waves
© EDP Sciences, 1998