SU(2) approach to the pseudogap phase of high-temperature superconductors: Electronic spectral functions

We use an SU(2) mean-field theory approach with input from variational wave functions of the t-J model to study the electronic spectra in the pseudogap phase of cuprates. In our model, the intermediate-temperature state of underdoped cuprates is realized by classical fluctuations of the order parameter between the d-wave superconductor and the staggered-flux state. The spectral functions of the pure and the averaged states are computed and analyzed. Our model predicts a photoemission spectrum with an asymmetric gap structure interpolating between the superconducting gap centered at the Fermi energy and the asymmetric staggered-flux gap. This asymmetry of the gap changes sign at the points where the Fermi surface crosses the diagonal (π,0)-(0,π).