Fractional-Charge Impurities in Semiconductors

This Letter predicts the existence of localized states in semiconductors associated with electrons or holes weakly bound to fractional-charge impurities, should fractional-charge particles exist in nature. The spectrum of excited states is rich enough to provide a detailed experimental signature for isolated fractional-charge particles. Theoretical estimates relevant to detection methods, sensitivity, and background signals indicate that one fractional charge per 10²¹-10²⁴ nucleons might be detectable.