MTP Seminar

Gautam Rai


"The superconducting proximity effect in quasicrystals"

Date: Thu, December 17, 2020
Time: 17:00
Place: online via zoom (please write the organizer for the meeting id and passcode)

Abstract: The term quasicrystals refers to a special class of materials that have no translational symmetry and yet have high amounts of long-range order—i.e. the Fourier transform of their atomic density consists of discrete delta-peaks. In crystals, this type of long-range order is easily understood to stem from the fact that a finite arrangement repeats itself indefinitely. In quasicrystals, a weaker condition is met—local configurations of any given size everywhere are almost alike at every scale. The discovery of a superconducting quasicrsytal in 2018 begs the question, how do correlated electrons behave in quasicrystals? We found that we could make considerable progress towards an answer to this question by considering the simplest possible model of a superconducting quasicrystal—the one-dimensional Fibonacci hopping model with pairing introduced via the Bogoliubov-de Gennes self-consistent field method. Today, I will primarily share results for proximity-induced superconductivity at a superconductor-quasicrystal interface. The highlight of the talk is the appearance of the topological gap labels of the Fibonacci chain in the amplitude of the induced order parameter.