Electron Green's function in the planar t-J model

The electron Green's functions G(k, w) within the t - J model and in the regime of intermediate doping is studied analytically using equations of motion for projected fermionic operators and the decoupling of the self energy into the single-particle and spin fluctuations. It is shown that the assumption of marginal spin dynamics at T = 0 leads to an anomalous quasiparticle damping. Numerical results show also a pronounced asymmetry between the hole (w < 0) and the electron (w > 0) part of the spectral function, whereby hole-like quasiparticles are generally overdamped.