Fractional quantization of the topological charge pumping in a one-dimensional superlattice
Fractional quantization of the topological charge pumping in a one-dimensional superlattice
A one-dimensional quantum charge pump transfers a quantized charge in each pumping cycle. This quantization is topologically robust being analogous to the quantum Hall effect. The charge transferred in a fraction of the pumping period is instead generally unquantized. We show, however, that with specific symmetries in parameter space the …