Argonne National Laboratory

Seminar Series

Date Title
Sep. 25, 2017 "Entanglements and Discrete Andreev States in Monolayer Organic Superconductor". Abdou Hassanien, Jozef Stefan Institute, Ljubljana, Solveia.  Host:  Yuan Zhang
 
Epitaxially grown monolayer of organic superconductor, (BETS)2GaCl4 [where BETS is bis(ethylenedithio)tetraselenafulvalene], on Ag(111) form islands of uniform and mixed stacking of 2-dimensional stripes. A d-wave superconducting gap, of magnitude 2? = 14 meV, is ubiquitously measured on uniform islands while been structurally altered on the inhomogeneous islands. Entanglements of superconducting intra-stripes are manifested by smeared anisotropy of the low energy quasiparticle as well as features of multigaps in their density of states. Despite proximal entanglements, the pronounced coherence peaks indicate well preserved superconducting state. Robust zero bias peaks are detected only at the edges of isolated stripes indicating tunneling into Andreev bound states. These features broaden significantly away from the edges due to quantum interference with nearby discrete states. The interplay between structural parameters and electronic properties makes single layer (BETS)2GaCl4 a unique playground for testing quantum computations.