Final Report Summary - CODE (Condensation in designed systems)
Bose-Einstein condensation is a phenomenon where particles prefer to behave in concert, as if they were a single particle, enforced by the laws of quantum mechanics. For instance lasers, used widely to power the internet, rely on the tendency of light particles to act coherently. Superconductivity, the ability of materials to conduct electricity without any energy losses, is also based on condensation of electron pairs. The goal of this project was to study how the phenomenon of condensation can be modified in systems where the particle’s properties are purposefully designed. The research led to two breakthroughs. First, it was found out by theoretical calculations that superconductivity is possible even if individual electrons do not move. This counterintuitive behaviour is possible because pairs of electrons can utilize for movement the geometrical properties of the lattice to which they are bound. Using such individually immobile electrons, the phenomenon of superconductivity can potentially be brought to room temperature where unprecedented applications in electricity transfer and information processing are possible. The second breakthrough was the first-ever experimental observation of a Bose-Einstein condensate in a plasmonic nanoparticle array. This new condensate is realized at room temperature, in a simple on-chip platform, and shows ultrafast dynamics: the formation of the condensate takes less than a trillionth of a second. The condensate is of interest for fundamental studies and has potential as a new type of future nanoscale light source.