2008/04/30 by Ribhu K. Kaul, Max A. Metlitski, Subir Sachdev +1 · 3 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.78.045110
published as Physical Review B 78, 045110 (2008) · 32 pages, 5 figures; (v3) Softened some claims and added references; (v4) Improved understanding of translational symmetry breaking in superconductor, added co-author
arxiv created 2008/06/11 · openalex publication_date 2008/07/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Motivated by the evidence in Pr_2\ensuremath-xCexCuO_4\ensuremath-y and Nd_2\ensuremath-xCexCuO_4\ensuremath-y of a magnetic quantum critical point at which N'eel order is destroyed, we study the evolution with doping of the T=0 quantum phases of the electron-doped cuprates. At low doping, there is a metallic N'eel state with small electron Fermi pockets, and this yields a fully gapped d_x2\ensuremath-y2 superconductor with coexisting N'eel order at low temperatures. We analyze the routes by which the spin-rotation symmetry can be restored in these metallic and superconducting states. In the metal, the loss of N'eel order leads to a topologically ordered ``doublon metal'' across a deconfined critical point with global O(4) symmetry. In the superconductor, in addition to the conventional spin-density wave transition, we find a variety of unconventional possibilities, including transitions to a nematic superconductor and to valence-bond supersolids. Measurements of the spin-correlation length and of the anomalous dimension of the N'eel order by neutron scattering or NMR should discriminate these unconventional transitions from spin-density wave theory.