Fractional Charge Pumping Of Interacting Bosons In One-Dimensional Superlattice

Motivated by experimental realizations of integer quantized charge pumping in one-dimensional superlattices [Nat. Phys. 12, 350 (2016); Nat. Phys. 12, 296 (2016)], we generalize and propose the adiabatic pumping of a fractionalized charge in interacting bosonic systems. This is achieved by dynamically sweeping the modulated potential in a class of one-dimensional interacting systems. As concrete examples, we show the charge pumping of interacting bosons at certain fractionally occupied fillings. We find that, for a given ground state, the charge pumping in a complete potential cycle is quantized to the fractional value related to the corresponding Chern number, characterized by the motion of the charge polarization per site. Moreover, the difference between charge polarizations of two ground states is quantized to an intrinsic constant revealing the fractional elementary charge of quasiparticle.