Fermi surface reconstruction inhigh-Tc superconductors

Abstract

The recent observation of quantum oscillations in underdopedhigh-Tc superconductors, combined with their negative Hall coefficient at low temperature, reveals thatthe Fermi surface of hole-doped cuprates includes a small electron pocket. This stronglysuggests that the large hole Fermi surface characteristic of the overdoped regime undergoesa reconstruction caused by the onset of some order which breaks translational symmetry. Herewe consider the possibility that this order is ‘stripe’ order, a form of combined charge/spinmodulation observed most clearly in materials like Eu-doped and Nd-doped LSCO(La2−xSrxCuO4). In these materials, the onset of stripe order coincides with major changes in transportproperties, providing strong evidence that stripe order is indeed the cause of Fermisurface reconstruction. We identify the critical doping where this reconstructionoccurs and show that the temperature dependence of transport coefficients atthat doping is typical of metals at a quantum critical point. We discuss how thepseudogap phase may be a fluctuating precursor of the stripe-ordered phase.