Single spin localization and manipulation in graphene open-shell nanostructures

Abstract

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.

Full text

Its licence does not allow us to show the full text. Read it at PubMed Central:

References 49

1. 1.

   Han W, Kawakami RK, Gmitra M, Fabian J. Graphene spintronics. Nat. Nanotechnol. 2014;9:794-807.

   Not in our library10.1038/nnano.2014.214

2. 2.

   Lieb EH. Two theorems on the hubbard model. Phys. Rev. Lett. 1989;62:1201.

   Not in our library10.1103/physrevlett.62.1201

3. 3.

   Yazyev OV, Helm L. Defect-induced magnetism in graphene. Phys. Rev. B. 2007;75:125408.

   Not in our library10.1103/physrevb.75.125408

4. 4.

   Nair RR, et al. Spin-half paramagnetism in graphene induced by point defects. Nat. Phys. 2012;8:199-202.

   Not in our library10.1038/nphys2183

5. 5.

   McCreary KM, Swartz AG, Han W, Fabian J, Kawakami RK. Magnetic moment formation in graphene detected by scattering of pure spin currents. Phys. Rev. Lett. 2012;109:186604.

   Not in our library10.1103/physrevlett.109.186604

6. 6.

   Gonzalez-Herrero H, et al. Atomic-scale control of graphene magnetism by using hydrogen atoms. Science. 2016;352:437-441.

   Not in our library10.1126/science.aad8038

7. 7.

   Fernández-Rossier J, Palacios JJ. Magnetism in graphene nanoislands. Phys. Rev. Lett. 2007;99:177204.

   Not in our library10.1103/physrevlett.99.177204

8. 8.

   Yazyev OV. Emergence of magnetism in graphene materials and nanostructures. Rep. Prog. Phys. 2010;73:056501.

   Not in our library10.1088/0034-4885/73/5/056501

9. 9.

   Alexandre SS, Lúcio AD, Castro Neto AH, Nunes RW. Correlated magnetic states in extended one-dimensional defects in graphene. Nano Lett. 2012;12:5097-5102.

   Not in our library10.1021/nl3017434

10. 10.

    Ortiz R, Lado JL, Melle-Franco M, Fernández-Rossier J. Engineering spin exchange in nonbipartite graphene zigzag edges. Phys. Rev. B. 2016;94:094414.

    Not in our library10.1103/physrevb.94.094414

11. 11.

    Morita Y, Suzuki S, Sato K, Takui T. Synthetic organic spin chemistry for structurally well-defined open-shell graphene fragments. Nat. Chem. 2011;3:197-204.

    Not in our library10.1038/nchem.985

12. 12.

    Son YW, Cohen ML, Louie SG. Half-metallic graphene nanoribbons. Nature. 2006;444:347-350.

    Not in our library10.1038/nature05180

13. 13.

    Tao C, et al. Spatially resolving spin-split edge states of chiral graphene nanoribbons. Nat. Phys. 2011;7:616-620.

    Not in our library10.1038/nphys1991

14. 14.

    Ruffieux P, et al. On-surface synthesis of graphene nanoribbons with zigzag edge topology. Nature. 2016;531:489-492.

    Not in our library10.1038/nature17151

15. 15.

    Yazyev OV, Capaz RB, Louie SG. Theory of magnetic edge states in chiral graphene nanoribbons. Phys. Rev. B. 2011;84:115406.

    Not in our library10.1103/physrevb.84.115406

16. 16.

    Carvalho AR, Warnes JH, Lewenkopf CH. Edge magnetization and local density of states in chiral graphene nanoribbons. Phys. Rev. B. 2014;89:245444.

    Not in our library10.1103/physrevb.89.245444

17. 17.

    Sepioni M, et al. Limits on intrinsic magnetism in graphene. Phys. Rev. Lett. 2010;105:207205.

    Not in our library10.1103/physrevlett.105.207205

18. 18.

    Nair RR, et al. Dual origin of defect magnetism in graphene and its reversible switching by molecular doping. Nat. Commun. 2013;4:2010.

    Not in our library10.1038/ncomms3010

19. 19.

    Li J, et al. Survival of spin state in magnetic porphyrins contacted by graphene nanoribbons. Sci. Adv. 2018;4:eaaq0582.

    Not in our library10.1126/sciadv.aaq0582

20. 20.

    Červenka J, Katsnelson MI, Flipse CFJ. Room-temperature ferromagnetism in graphite driven by two-dimensional networks of pointdefects. Nat. Phys. 2009;5:840-844.

    Not in our library10.1038/nphys1399

21. 21.

    Kondo J. Resistance minimum in dilute magnetic alloys. Prog. Theor. Phys. 1964;32:37-49.

    Not in our library10.1143/ptp.32.37

22. 22.

    Ternes M, Heinrich AJ, Schneider WD. Spectroscopic manifestations of the Kondo effect on single adatoms. J. Phys. Condens. Matter. 2009;21:053001.

    Not in our library10.1088/0953-8984/21/5/053001

23. 23.

    Dienel T, et al. Resolving atomic connectivity in graphene nanostructure junctions. Nano Lett. 2015;15:5185-5190.

    Not in our library10.1021/acs.nanolett.5b01403

24. 24.

    de Oteyza DG, et al. Substrate-independent growth of atomically precise chiral graphene nanoribbons. ACS Nano. 2016;10:9000-9008.

    Not in our library10.1021/acsnano.6b05269

25. 25.

    Merino-Díez N, et al. Unraveling the electronic structure of narrow atomically precise chiral graphene nanoribbons. J. Phys. Chem. Lett. 2018;9:25-30.

    Not in our library10.1021/acs.jpclett.7b02767

26. 26.

    Shiotari A, et al. Strain-induced skeletal rearrangement of a polycyclic aromatic hydrocarbon on a copper surface. Nat. Commun. 2017;8:16089.

    Not in our library10.1038/ncomms16089

27. 27.

    Fernández-Torrente I, Franke KJ, Pascual JI. Vibrational Kondo effect in pure organic charge-transfer assemblies. Phys. Rev. Lett. 2008;101:217203.

    Not in our library10.1103/physrevlett.101.217203

28. 28.

    Zhang Yh, et al. Temperature and magnetic field dependence of a kondo system in the weak coupling regime. Nat. Commun. 2013;4:2110.

    Not in our library10.1038/ncomms3110

29. 29.

    Nagaoka K, Jamneala T, Grobis M, Crommie MF. Temperature dependence of a single Kondo impurity. Phys. Rev. Lett. 2002;88:77205.

    Not in our library10.1103/physrevlett.88.077205

30. 30.

    Hirjibehedin CF, Lutz CP, Heinrich AJ. Spin coupling in engineered atomic structures. Science. 2006;312:1021-1024.

    Not in our library10.1126/science.1125398

31. 31.

    Ternes M. Spin excitations and correlations in scanning tunneling spectroscopy. New J. Phys. 2015;17:63016.

    Not in our library10.1088/1367-2630/17/6/063016

32. 32.

    Heersche HB, et al. Kondo effect in the presence of magnetic impurities. Phys. Rev. Lett. 2006;96:017205.

    Not in our library10.1103/physrevlett.96.017205

33. 33.

    Paaske J, et al. Non-equilibrium singlet-triplet kondo effect in carbon nanotubes. Nat. Phys. 2006;2:460-464.

    Not in our library10.1038/nphys340

34. 34.

    Ortiz R, García-Martínez NA, Lado JL, Fernández-Rossier J. Electrical spin manipulation in graphene nanostructures. Phys. Rev. B. 2018;97:195425.

    Not in our library10.1103/physrevb.97.195425

35. 35.

    Pavliček N, et al. Synthesis and characterization of triangulene. Nat. Nanotechnol. 2017;12:308-311.

    Not in our library10.1038/nnano.2016.305

36. 36.

    Talirz L, et al. Termini of bottom-up fabricated graphene nanoribbons. J. Am. Chem. Soc. 2013;135:2060-2063.

    Not in our library10.1021/ja311099k

37. 37.

    Koch M, Ample F, Joachim C, Grill L. Voltage-dependent conductance of a single graphene nanoribbon. Nat. Nanotechnol. 2012;7:713-717.

    Not in our library10.1038/nnano.2012.169

38. 38.

    Jasper-Tönnies T, et al. Conductance of a freestanding conjugated molecular wire. Phys. Rev. Lett. 2017;119:066801.

    Not in our library10.1103/physrevlett.119.066801

39. 39.

    Choi DJ, Abufager P, Limot L, Lorente N. From tunneling to contact in a magnetic atom: the non-equilibrium kondo effect. J. Chem. Phys. 2017;146:092309.

    Not in our library10.1063/1.4972874

40. 40.
    Giant edge state splitting at atomically precise graphene zigzag edges · 2016

    No notice
41. 41.

    Li Y, Zhang W, Morgenstern M, Mazzarello R. Electronic and magnetic properties of zigzag graphene nanoribbons on the (111) surface of Cu, Ag, and Au. Phys. Rev. Lett. 2013;110:216804.

    Not in our library10.1103/physrevlett.110.216804

42. 42.

    Ruffieux P, et al. Electronic structure of atomically precise graphene nanoribbons. ACS Nano. 2012;6:6930-6935.

    Not in our library10.1021/nn3021376

43. 43.

    Merino-Díez N, et al. Width-dependent band gap in armchair graphene nanoribbons reveals Fermi level pinning on Au(111). ACS Nano. 2017;11:11661-11668.

    Not in our library10.1021/acsnano.7b06765

44. 44.

    Soler JM, et al. The siesta method for ab initio order-n materials simulation. J. Phys. Condens. Matter. 2002;14:2745-2779.

    Not in our library10.1088/0953-8984/14/11/302

45. 45.

    Ceperley DM, Alder BJ. Ground state of the electron gas by a stochastic method. Phys. Rev. Lett. 1980;45:566-569.

    Not in our library10.1103/physrevlett.45.566

46. 46.

    Perdew JP, Burke K, Ernzerhof M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1996;77:3865-3868.

    Not in our library10.1103/physrevlett.77.3865

47. 47.

    Hancock Y, Uppstu A, Saloriutta K, Harju A, Puska MJ. Generalized tight-binding transport model for graphene nanoribbon-based systems. Phys. Rev. B. 2010;81:245402.

    Not in our library10.1103/physrevb.81.245402

48. 48.

    Papior, N. R. sisl: v0.9. 2. 10.5281/zenodo.597181 (2018).

    Not in our library

49. 49.

    Frota HO. Shape of the Kondo resonance. Phys. Rev. B. 1992;45:1096-1099.

    Not in our library10.1103/physrevb.45.1096

Cited by papers we hold 1

• Nanographenes and Graphene Nanoribbons as Multitalents of Present and Future Materials Science · 2022
  No notice

Reads

A person counts once a day per paper. We keep no cookie and no address: a reader is a hash that changes every day. Any month under five reads shows no number.