Mean-Field Pairing Theory for the Charge-Stripe Phase of High-Temperature Cuprate Superconductors

摘要

Striped high-T_c superconductors such as La_(2-y-x)Nd_ySr_xCuO-4 and La-(2-x)Ba-xCuO-4 near x = 1/8 show a fascinating competition between spin and charge order and superconductivity. A theory for these systems therefore has to capture both the spin correlations of an antiferromagnet and the pair correlations of a superconductor. For this purpose we present here an effective Hartree-Fock theory incorporating both electron pairing with finite center-of-mass momentum and antiferromagnetism. We show that this theory reproduces the key experimental features such as the formation of the antiferromagnetic stripe patterns at 7/8 band filling or the quasi-one-dimensional electronic structure observed by photoemission spectroscopy.