Shiba duality and $\eta$-altermagnetism: Pairing and charge orders in bipartite attractive Hubbard models

Yu-Ping Lin

We show that Shiba duality maps the altermagnetic principle of momentum-dependent band splitting from spin to $\eta$-pseudospin, defining $\eta$-altermagnetism ($\eta$-ALM) as a Bogoliubov-…