Strong correlation effects and optical conductivity in electron-doped cuprates
Physics Department, Northeastern University - Boston, MA 02115, USA
2 Theoretical Division, Los Alamos National Laboratory - Los Alamos, NM 87545, USA
Accepted: 31 August 2011
We demonstrate that most features ascribed to strong correlation effects in various spectroscopies of the electron-doped cuprates are captured by a calculation of the self-energy incorporating effects of spin and charge fluctuations. The self-energy is calculated over the full doping range of electron-doped cuprates from half filling to the overdoped system. The self-energy devides the low-energy physics of cuprates into two energy scales: an antiferromagnetic (AFM) “pseudogap” region near the Fermi level and a high-energy “Mott gap region”. The corresponding spectral function reveals four subbands, two widely split incoherent bands representing the remnant of the split Hubbard bands, and two additional coherent, spin- and charge-dressed in-gap bands split by a spin-density-wave, which collapses in the overdoped regime. The incoherent features persist to high doping, producing a remnant Mott gap in the optical spectra, while transitions between the in-gap states lead to AFM pseudogap features in the mid-infrared.
PACS: 74.25.Gz – Optical properties / 74.72.-h – Cuprate superconductors / 74.20.Mn – Nonconventional mechanisms
© EPLA, 2011