Fractionally quantized Berry phases of magnetization plateaux in spin-$1/2$ Heisenberg multimer chains

Isao Maruyama, Shin Miyahara

We study the fractionally quantized $Z_N$ Berry phase, ${\gamma }_N=0,\frac{2\pi }{N},\frac{4\pi }{N},\dots ,\frac{2(N-1)\pi }{N}$, to characterize local $N$-mer spin structures at magnetization pl…