Coexisting pseudogap, charge-transfer-gap, and Mott-gap energy scales in the resonant inelastic x-ray scattering spectra of electron-doped cuprate superconductors

Susmita Basak, Northeastern University
Tanmoy Das, Northeastern University
Hsin Lin, Northeastern University
M. z. Hasan, Princeton University
R. S. Markiewicz, Northeastern University
A. Bansil, Northeastern Univeristy

Article comments

Originally published in Physical Review B v.85 (2012): 075104. DOI: 10.1103/PhysRevB.85.075104

Abstract

We present a computation of Cu K-edge resonant inelastic x-ray scattering (RIXS) spectra for electron-doped cuprates, which includes coupling to bosonic fluctuations. Comparison with experiment over a wide range of energy and momentum transfers allows us to identify the signatures of three key normal-state energy scales: the pseudogap, charge-transfer gap, and Mott gap. The calculations involve a three-band Hubbard Hamiltonian based on dₓ²₋_y² and O pₓ, p_y orbitals, with a self-energy correction which arises due to spin and charge fluctuations. Our theory reproduces characteristic features, e.g., gap collapse, large spectral weight broadening, and spectral weight transfer as a function of doping, as seen in experiments.