Spin orthogonality catastrophe in two-dimensional antiferromagnets and superconductors

Abstract

We compute the spectral function of a spin S hole injected into a two-dimensional antiferromagnet or superconductor in the vicinity of a magnetic quantum critical point. We show that, near van Hove singularities, the problem maps onto that of a static vacancy carrying excess spin S. The hole creation operator is characterized by a new boundary anomalous dimension and a vanishing quasiparticle residue at the critical point. We discuss possible relevance to photoemission spectra of cuprate superconductors near the anti-nodal points.

(v1) 4 pages, 2 figures; field theory afficionados - see also cond-mat/0011233; (v2) added figure of Monte Carlo data; (v3) corrected typos