Pairs and stripes phases in an antiferromagnet within the extended Hubbard model.

The conduction mechanism is the key to understanding superconductivity in materials. Cooper pairs are the charge carriers in superconductivity, but stripe-type phases are also found in type II superconductors [1,2] and might be important for high-temperature superconductivity [3]. In this work, we present a pairing mechanism in a two-dimensional antiferromagnetic material within the extended Hubbard model with repulsive electron-electron interaction and Ising-type spin interactions at different band occupancy levels. This model can show that charge transport is via hole pairs or stripe-type phases and also presents charge expulsion. The effects of repulsion and carrier concentration on he conduction mechanism are discussed. It is shown how the competition between kinetic energy, Coulombic repulsion and antiferromagnetic order can lead to complex electronic structures and transport mechanisms.

Bibliography:

[1] Emery VJ, Kivelson SA, Tranquada JM. Stripe phases in high-temperature superconductors. Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8814-7

[2] Zheng, Bo-Xiao, Chia-Min Chung, Philippe Corboz, Georg Ehlers, Ming-Pu Qin, Reinhard M. Noack, Hao Shi, Steven R. White, Shiwei Zhang, and Garnet Kin-Lic Chan. 2017. “Stripe Order in the Underdoped Region of the Two-dimensional Hubbard Model”. Science 358 (6367): 1155–60.

[3] Park, S., Kim, S.Y., Kim, H.K. et al. Superconductivity emerging from a stripe charge order in IrTe2 nanoflakes. Nat Commun 12, 3157 (2021).