Field-induced electric polarization and elastic softening caused by parity-mixed $d$-$p$ hybridized states with electric multipoles in Ba${}_2$CuGe${}_2$O${}_7$

R. Kurihara, Y. Sato, A. Miyake +5

We performed high-magnetic-field magnetization, polarization, and ultrasonic measurements in Ba${}_2$CuGe${}_2$O${}_7$ to investigate field-induced multiferroic properties arising from a…