Helical order and multiferroicity in the $S=1/2$ quasi-kagome system KCu${}_3$As${}_2$O${}_7$(OD)${}_3$

Gøran J. Nilsen, Yoshihiko Okamoto, Hajime Ishikawa +7

Several Cu${}^{2+}$ hydroxide minerals have recently been identified as candidate realizations of the $S=1/2$ kagome Heisenberg model. In this context, we have studied the distorted…