Controlling zero bias anomalies in magnetic atoms provides a promising strategy to engineer tunable quantum many-body excitations. Here we show how two different quantum impurities featuring spinaron and Kondo excitations can be controlled via quantum confinement engineering by using circular quantum corrals on a Ag(111) surface. In corrals built from both Ag and Co adatoms, the width of the zero bias anomaly in the central Co adatom oscillates as a function of corral radius with a period of half of the Ag(111) surface state wavelength. Parameters extracted for Co/Ag(111) show only small differences in extracted spinaron zero-bias anomaly between corral walls built from Ag or Co adatoms. In quantum corrals occupied with metal-free phthalocyanine, a S=1/2 Kondo system, we observe notable changes in the zero bias anomaly lineshape as a function of corral radius. Our results offer insight into many-body Kondo and spinaron resonances where the electronic density is controlled by confinement engineering.
@article{arxiv.2312.03364,
title = {Tuning spinaron and Kondo resonances via quantum confinement},
author = {Markus Aapro and Abraham Kipnis and Jose L. Lado and Shawulienu Kezilebieke and Peter Liljeroth},
journal= {arXiv preprint arXiv:2312.03364},
year = {2024}
}