Pairing symmetry in the superconducting state coexisting with antiferromagnetic order is studied based on a microscopic theory. We calculate the linearized Eliashberg's equation within the random phase approximation in the Hubbard model with a staggered field. We find that odd-frequency spin-triplet (equal-spin) s-wave pairing state can be realized. This result contradicts a naive expectation that antiferromagnetic order induces antiferromagnetic spin fluctuation and favors spin-singlet d-wave pairing as in the standard strongly correlated systems.
@article{arxiv.1104.4693,
title = {Pairing symmetry of superconductivity coexisting with antiferromagnetism},
author = {Keisuke Shigeta and Seiichiro Onari and Yukio Tanaka},
journal= {arXiv preprint arXiv:1104.4693},
year = {2013}
}