Electron momentum distribution of a single mobile hole in the t-J model

We investigate the electron momentum distribution function (EMDF) for the t wo-dimensional t-J model. The results are based on the self-consistent Born approximation (SCBA) for the self-energy and the wave function. In the Isi ng limit of the model we give the results in a closed form, in. the Heisenb erg limit the results are obtained numerically. An anomalous momentum depen dence of EMDF is found and the anomaly is in the lowest order in number of magnons expressed analitycally. We interpret the anomaly as a fingerprint o f an emerging large Fermi surface coexisting with hole pockets.