Quantum spin ladder with ferromagnetic rungs in Bi${}_2$CuO${}_3$(SO${}_4$)

Rodolfo A. Rangel Hernandez, Kirill Yu. Povarov, Sergei Zvyagin +3

We introduce Bi${}_2$CuO${}_3$(SO${}_4$) as a rare example of a spin-ladder magnet with ferromagnetic interactions on the rungs. Its magnetic response is studied through measurements of…