Enhanced dielectric response by disordered nanoscale/mesoscopic   insulators
  Enhancement of the dielectric response of insulators by disorder is theoretically proposed, where the quantum interference of electronic waves through the nanoscale/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. Realization of this idea with accessible materials/structures is also discussed. 
Shigeki Onoda, Chyh-Hong Chern, Shuichi Murakami, Yasushi Ogimoto,   Naoto Nagaosa