Topological order, emergent gauge fields, and Fermi surface reconstruction.

摘要: This review describes how topological order associated with the presence of emergent gauge fields can reconstruct Fermi surfaces metals, even in absence translational symmetry breaking. We begin an introduction to using Wegner's quantum [Formula: see text] theory on square lattice: state is characterized by expulsion defects, carrying magnetic flux. The interplay between and breaking global described non-zero temperature statistical mechanics classical XY models dimension D  =  3; such also describe zero phases bosons short-range interactions lattice at integer filling. again certain a fluctuating symmetry-breaking order, along fields. phase diagrams are obtained embedding them U(1) theories, studying their Higgs confining phases. These ideas then applied single-band Hubbard model lattice. A SU(2) fluctuations spin-density-wave its diagram presented analogy models. obtain class metallic states spin-density wave defect expulsion, deconfined fields, reconstructed (with 'chargon' or electron-like quasiparticles), but no broken symmetry. conclude application pseudogap cuprates, note recent comparison numerical studies photoemission observations electron-doped cuprates. In detour, we discuss influence Berry phases, they lead critical points: this applies half-integer filling, dimer