Disorder-enhanced dielectric response of nanoscale and mesoscopic insulators

Enhancement of the dielectric response of insulators by disorder is theoretically proposed, where the quantum interference of electronic waves through the nanoscale or mesoscopic system and its change due to external perturbations control the polarization. In the disordered case with all the states being localized, the resonant tunneling, which is topologically protected, plays a crucial role, and enhances the dielectric response by a factor 30-40 compared with the pure case. The realization of this idea with accessible materials or structures is also discussed.