Topological frustration induces unconventional magnetism in a nanographene


JSON Export

{
  "id": "460", 
  "updated": "2020-07-15T16:19:24.947897+00:00", 
  "metadata": {
    "description": "The chemical versatility of carbon imparts manifold properties to organic compounds, where magnetism remains one of the most desirable but elusive. Polycyclic aromatic hydrocarbons, also referred to as nanographenes, show a critical dependence of electronic structure on the topologies of the edges and the \u03c0-electron network, which makes them model systems with which to engineer unconventional properties including magnetism. In 1972, Erich Clar envisioned a bow-tie-shaped nanographene, C38H18, where topological frustration in the \u03c0-electron network renders it impossible to assign a classical Kekul\u00e9 structure without leaving unpaired electrons, driving the system into a magnetically non-trivial ground state. In this record we include data needed to support our recent work where we demonstrate the experimental realization and in-depth characterization of this emblematic nanographene, known as Clar\u2019s goblet. Scanning tunnelling microscopy and spin excitation spectroscopy of individual molecules on a gold surface reveal a robust antiferromagnetic order with an exchange-coupling strength of 23\u2009meV, exceeding the Landauer limit of minimum energy dissipation at room temperature. Through atomic manipulation, we realize switching of magnetic ground states in molecules with quenched spins. Our results provide direct evidence of carbon magnetism in a hitherto unrealized class of nanographenes, and prove a long-predicted paradigm where topological frustration entails unconventional magnetism, with implications for room-temperature carbon-based spintronics.", 
    "contributors": [
      {
        "affiliations": [
          "nanotech@surfaces Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, D\u00fcbendorf, Switzerland"
        ], 
        "givennames": "Shantanu", 
        "familyname": "Mishra"
      }, 
      {
        "affiliations": [
          "Faculty of Chemistry and Food Chemistry, and Center for Advancing Electronics Dresden, Technical University of Dresden, Dresden, Germany"
        ], 
        "givennames": "Doreen", 
        "familyname": "Beyer"
      }, 
      {
        "affiliations": [
          "nanotech@surfaces Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, D\u00fcbendorf, Switzerland"
        ], 
        "givennames": "Kristjan", 
        "familyname": "Eimre"
      }, 
      {
        "affiliations": [
          "Department of Applied Physics, Aalto University, Espoo, Finland"
        ], 
        "givennames": "Shawulienu", 
        "familyname": "Kezilebieke"
      }, 
      {
        "affiliations": [
          "Faculty of Chemistry and Food Chemistry, and Center for Advancing Electronics Dresden, Technical University of Dresden, Dresden, Germany"
        ], 
        "givennames": "Reinhard", 
        "familyname": "Berger"
      }, 
      {
        "email": "oliver.groening@empa.ch", 
        "givennames": "Oliver", 
        "affiliations": [
          "nanotech@surfaces Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, D\u00fcbendorf, Switzerland"
        ], 
        "familyname": "Gr\u00f6ning"
      }, 
      {
        "email": "carlo.pignedoli@empa.ch", 
        "givennames": "Carlo A.", 
        "affiliations": [
          "nanotech@surfaces Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, D\u00fcbendorf, Switzerland"
        ], 
        "familyname": "Pignedoli"
      }, 
      {
        "affiliations": [
          "Department of Synthetic Chemistry, Max Planck Institute for Polymer Research, Mainz, Germany"
        ], 
        "givennames": "Klaus", 
        "familyname": "M\u00fcllen"
      }, 
      {
        "affiliations": [
          "Department of Applied Physics, Aalto University, Espoo, Finland"
        ], 
        "givennames": "Peter", 
        "familyname": "Liljeroth"
      }, 
      {
        "affiliations": [
          "nanotech@surfaces Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, D\u00fcbendorf, Switzerland"
        ], 
        "givennames": "Pascal", 
        "familyname": "Ruffieux"
      }, 
      {
        "affiliations": [
          "Faculty of Chemistry and Food Chemistry, and Center for Advancing Electronics Dresden, Technical University of Dresden, Dresden, Germany"
        ], 
        "givennames": "Xinliang", 
        "familyname": "Feng"
      }, 
      {
        "email": "roman.fasel@empa.ch", 
        "givennames": "Roman", 
        "affiliations": [
          "nanotech@surfaces Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, D\u00fcbendorf, Switzerland", 
          "Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland"
        ], 
        "familyname": "Fasel"
      }
    ], 
    "title": "Topological frustration induces unconventional magnetism in a nanographene", 
    "license_addendum": null, 
    "mcid": "2020.79", 
    "id": "460", 
    "is_last": true, 
    "_oai": {
      "id": "oai:materialscloud.org:460"
    }, 
    "publication_date": "Jul 15, 2020, 18:19:24", 
    "edited_by": 100, 
    "status": "published", 
    "version": 1, 
    "license": "Creative Commons Attribution 4.0 International", 
    "_files": [
      {
        "key": "ReadMe.yaml", 
        "size": 39630, 
        "description": "ReadME file in yaml format describing the files contained in the record", 
        "checksum": "md5:45b8c0308fac66ab0c6c0e681719d67d"
      }, 
      {
        "key": "data.tgz", 
        "size": 24369874, 
        "description": "tar archive with teh files listed in ReadME.yaml", 
        "checksum": "md5:1eaefa2ff9c927c414a7ae4d2047974e"
      }, 
      {
        "key": "calculations.aiida", 
        "size": 166586850, 
        "description": "AiiDA archive with nodes of the calculations done with AiiDA", 
        "checksum": "md5:9c75df2285b99f412e2e698a75db1a23"
      }
    ], 
    "owner": 26, 
    "keywords": [
      "MARVEL/DD3", 
      "SNSF", 
      "ERC", 
      "Clar goblet", 
      "Kondo", 
      "nanographene", 
      "ab initio"
    ], 
    "references": [
      {
        "type": "Journal reference", 
        "doi": "10.1038/s41565-019-0577-9", 
        "citation": "S. Mishra, D. Beyer, K. Eimre, S. Kezilebieke, R. Berger, O. Gr\u00f6ning, C.A. Pignedoli, K. M\u00fcllen, P. Liljeroth, P. Ruffieux, X. Feng and R. Fasel,\nNat. Nanotechnol. 15, 22-28 (2020)"
      }
    ], 
    "conceptrecid": "459", 
    "doi": "10.24435/materialscloud:ha-t5"
  }, 
  "revision": 6, 
  "created": "2020-07-09T09:42:51.269396+00:00"
}