The role of confinement and interaction in the emergence of aromatic features in nanoscale synthetic molecules

It has recently been demonstrated that the electronic structure of polyaromatic hydrocarbons can be qualitatively reproduced by quantum corrals made via atomic manipulation. This presents a quandary since the electronic structure of these molecules has been ascribed to a resonating valence bond like state requiring strong confinement to molecular orbitals and significant electron-electron interactions. However, quantum corrals fundamentally exhibit single-electron physics as evidenced by a short lifetime for an electron in a corral, resulting in the absence of Coulomb effects between electrons. We examine this problem from the experimental data obtained via scanning tunneling spectroscopy and topography, tight-binding modeling of hopping and interaction Hamiltonians, as well as density functional theory calculations to determine what aspects of the fully-interacting picture can be produced by the single-electron approach.