F. Javier García de Abajo

Institut de Ciències Fotòniques (ICFO)

Having new methods to synthesize previously non-existing materials constitutes a challenge with important consequences for technological progress in general. Unfortunately, there is a limited suite of methods for material design, essentially consisting in changing the chemical composition and the microscopic structure of already existing materials. This work introduces a disruptive approach to materials design, producing radical modifications in the electronic properties, the optical response, and the thermal conduction of a thin atomic layer, and essentially rendering a previously non-existing material. The new method relies on imprinting a so-called quantum phase on the material’s electrons by means of non-contact interaction with an external structure. The latter does not need to produce external fields, in contrast to electric or magnetic doping schemes, so the present approach is highly noninvasive. This method is thus exploiting a genuinely quantum effect to modify, with a substantial degree of control, the material’s properties. In particular, the work demonstrates, based on rigorous theory, that electronic gaps are opened in a doped thin superconductor by the aforementioned quantum interaction with a neighboring neutral structure, and this in turn produces radical changes in the optical response, as well as a metal-insulator transition in its electrical behavior, accompanied by a thermal conductor-insulator transition. In brief, this work introduces a viable, disruptive, conceptually novel approach to materials design, thus enriching the limited suite of tools that are currently available to engineer materials for application in the design of nanodevices.