Higher-order corrections in the hole spectral function using the finite temperature Green's function method
In this paper, higher-order corrections in the hole spectral function is calculated using the finite temperature (Matsubara) Green's function method in the spin polaron formulation. The spin polaron Hamiltonian was used as the interaction term in the S-matrix expansion. Second-order terms to the hole spectral function are presented. Higher-order corrections are briefly discussed.