The multiconfigurational ground state of a diradicaloid characterized at the atomic scale

TL;DR

This study demonstrates the atomic-scale characterization of a singlet diradicaloid molecule with a many-body ground state, revealing strong electronic correlations through advanced microscopy and theoretical calculations.

Contribution

It provides the first atomic-scale experimental evidence of a multiconfigurational ground state in a diradicaloid molecule, combining microscopy and multiconfigurational calculations.

Findings

Revealed bond-order contrast along the C$_{4}$ chain.

Mapped charge-state transitions indicating electronic correlations.

Confirmed many-body ground state through combined experimental and theoretical analysis.

Abstract

We report the tip-induced generation and scanning probe characterization of a singlet diradicaloid, consisting of two phenalenyl units connected by an sp-hybridized C$_{4}$ chain, on an ultrathin insulating NaCl surface. The bond-order contrast along the C$_{4}$ chain measured by atomic force microscopy and mapping of charge-state transitions by scanning tunneling microscopy, in conjunction with multiconfigurational calculations, reveal that the molecule exhibits a many-body ground state. Our study experimentally demonstrates the manifestation of strong electronic correlations in the geometric and electronic structures of a single molecule.