Fractional boundary charges in quantum dot arrays with density modulation

TL;DR

This paper demonstrates that fractional boundary charges can be engineered in quantum dot arrays with periodic potential modulation, offering tunability and robustness against disorder, expanding potential applications in quantum electronics.

Contribution

It introduces a method to realize and control fractional boundary charges in quantum dot arrays with density modulation, showing their stability and tunability.

Findings

Fractional boundary charges can be tuned by potential phase and array size.

These charges are stable against static disorder.

Minimum array size for observing fractional charges is discussed.

Abstract

We show that fractional charges can be realized at the boundaries of a linear array of tunnel coupled quantum dots in the presence of a periodically modulated onsite potential. While the charge fractionalization mechanism is similar to the one in polyacetylene, here the values of fractional charges can be tuned to arbitrary values by varying the phase of the onsite potential or the total number of dots in the array. We also find that the fractional boundary charges, unlike the in-gap bound states, are stable against static random disorder. We discuss the minimum array size where fractional boundary charges can be observed.