Single spin localization and manipulation in graphene open-shell nanostructures

Main Authors: Jingcheng Li, Sofia Sanz, Martina Corso, Deung Jang Choi, Diego Peña, Thomas Frederiksen, Jose Ignacio Pascual
Format: Article eJournal
Bahasa: eng
Terbitan: , 2019
Online Access: https://zenodo.org/record/3686585
Daftar Isi:
  • Turning graphene magnetic is a promising challenge to make it an active material for spintronics. Predictions state that graphene structures with specific shapes can spontaneously develop magnetism driven by Coulomb repulsion of π-electrons, but its experimental verification is demanding. Here, we report on the observation and manipulation of individual magnetic moments in graphene open-shell nanostructures on a gold surface. Using scanning tunneling spectroscopy, we detect the presence of single electron spins localized around certain zigzag sites of the carbon backbone via the Kondo effect. We find near-by spins coupled into a singlet ground state and quantify their exchange interaction via singlet-triplet inelastic electron excitations. Theoretical simulations picture how electron correlations result in spin-polarized radical states with the experimentally observed spatial distributions. Extra hydrogen atoms bound to radical sites quench their magnetic moment and switch the spin of the nanostructure in half-integer amounts. Our work demonstrates the intrinsic π-paramagnetism of graphene nanostructures.