Slave Particle Studies of the Electron Momentum Distribution in the Low Dimensional $t-J$ Model

TL;DR

This study uses a slave particle approach to analyze the electron momentum distribution in the low-dimensional $t-J$ model, revealing limitations in explaining experimental Fermi surface observations and the importance of nonlocal string fields.

Contribution

It provides a detailed analysis within the slave particle framework, highlighting its inability to fully reproduce experimental Fermi surface features and emphasizing the need for nonlocal effects.

Findings

Fails to explain observed electron Fermi surface in experiments.

Does not obey the sum rule for physical electrons.

Reproduces correct scaling behavior near $k_F$ with nonlocal string fields.

Abstract

The electron momentum distribution function in the $t-J$ model is studied in the framework of slave particle approach. Within the decoupling scheme used in the gauge field and related theories, we treat formally phase and amplitude fluctuations as well as constraints without further approximations. Our result indicates that the electron Fermi surface observed in the high-resolution angle-resolved photoemission and inverse photoemission experiments cannot be explained within this framework, and the sum rule for the physical electron is not obeyed. A correct scaling behavior of the electron momentum distribution function near $k \sim k_{F}$ and $k \sim 3k_{F}$ in one dimension can be reproduced by considering the nonlocal string fields [Z. Y. Weng et al., Phys. Rev. B45, 7850 (1992)], but the overall momentum distribution is still not correct, at least at the mean field level.