(Topological) superconductivity in atomically thin metals

Since the "Graphene Revolution", much progress has been made in fabrication and understanding of one-monolayer-thick two dimensional crystals. Until recently, it was believed superconductivity - the property exhibited by some materials where below a certain temperature, all electrical resistance is lost - could not exist in such systems. When superconductivity was experimentally observed in a monolayer of Pb deposited on a Si substrate, it triggered a debate on the exact origin of this phenomenon. In parallel, tin (Sn), apart from being an elementalsuperconductor, was found to be a topological insulator in the 2D limit (dubbed "stanene" in analogy to graphene), with ability to conduct electricity perfectly on the edges, while remaining insulating in the interior. This edge superconductivity is extremely robust against impurities or thermal fluctuations, making stanene one of the prime candidates for advanced technological applications.This is the setting in which the proposed research on "topological superconductivity" will take place. We aim to study the behaviour of several different metals in the two dimensional limit: first a single atomic layer, then increasing the number of layers one at a time, and analyze the electronic and phonon spectra using state-of-the-art numerical techniques. This will give access to the topological nature of the electrons, as well as shed light on the reasons of nucleation and pathways of evolution of superconductivity, in a close relationship with available experiments. Given the impact that both superconductivity and topological insulators have had on research so far, the fundamental and technological relevance of this research can hardly be overstated.

Keywords:FUNCTIONAL CHARACTERISATION, ATOMISTIC SIMULATIONS, TOPOLOGICAL SUPERCONDUCTIVITY, MONOLAYER MATERIALS

Disciplines:Condensed matter physics and nanophysics, Analytical chemistry, Macromolecular and materials chemistry