Seminário Extra: Disordered hyperuniformity in two dimensional binary mixtures

Palestrante: Prof. Enrique Lomba – IQFR-CSIC, Madrid, Spain & Department of Chemistry, Princeton University

Título: Disordered hyperuniformity in two dimensional binary mixtures

Resumo: Disordered hyperuniform systems1 have been shown to be new topological states of matter which share a number of features with crystals, e.g. the presence of a certain kind of long range order, and fluids (lack of short range order). This type of microscopic structure is known to cancel long range density fluctuations –by which they present a vanishing structure factor as the wave number goes to zero-. Disordered hyperuniformity has been shown to occur in materials as diverse as chicken retina, some amorphous semiconductors, and stealth materials2. In this presentation, we will show how hyperuniformity can be induced in a disordered system by the presence of a purely repulsive Coulomb interaction (characteristic of charged plasmas) in a system of non-additive hard disks. This system, depending on the character of the nonadditivity can exhibit either demixing, or hetero-coordination. The interplay between long-ranged hyperuniformity effects and short range order will be illustrated and its influence on the microscopic structure and the system’s critical behaviour will be analysed. Moreover, we will show how tuning the cross interactions can induce multi-hyperuniformity3, a topological state in which each component exhibits a hyperuniform structure, which is the very special feature characterizing the spatial distribution of avian photoreceptors.