The use of molecular spin state as a quantum of information for storage, sensing and computing has generated considerable interest in the context of next-generation data storage and communication devices1,2, opening avenues for developing multifunctional molecular spintronics3. Such ideas have been researched extensively, using single-molecule magnets4,5 and molecules with a metal ion6 or nitrogen vacancy7 as localized spin-carrying centres for storage and for realizing logic operations8. However, the electronic coupling between the spin centres of these molecules is rather weak, which makes construction of quantum memory registers a challenging task9. In this regard, delocalized carbon-based radical species with unpaired spin, such as phenalenyl10, have shown promise. These phenalenyl moieties, which can be regarded as graphene fragments, are formed by the fusion of three benzene rings and belong to the class of open-shell systems. The spin structure of these molecules responds to external stimuli11,12 (such as light, and electric and magnetic fields), which provides novel schemes for performing spin memory and logic operations. Here we construct a molecular device using such molecules as templates to engineer interfacial spin transfer resulting from hybridization and magnetic exchange interaction with the surface of a ferromagnet; the device shows an unexpected interfacial magnetoresistance of more than 20 per cent near room temperature. Moreover, we successfully demonstrate the formation of a nanoscale magnetic molecule with a well-defined magnetic hysteresis on ferromagnetic surfaces. Owing to strong magnetic coupling with the ferromagnet, such independent switching of an adsorbed magnetic molecule has been unsuccessful with single-molecule magnets13. Our findings suggest the use of chemically amenable phenalenyl-based molecules as a viable and scalable platform for building molecular-scale quantum spin memory and processors for technological development.

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We thank J. M. D. Coey of Trinity College, Ireland, for discussions. K.V.R. and J.S.M. were supported by the Office of Naval Research (ONR grant N00014-09-1-0177) and the National Science Foundation (grants DMR 0504158 and ULFR 09-0532-01). A.M.K. thanks the University of Groningen for partial financial support during his stay at MIT. N.A. and V.C. thank the Julich Supercomputing Centre, Forschungszentrum Julich (Germany), for performing calculations on JUROPA and JUGENE supercomputers. A.M. and T.K.S. thank IISER-Kolkata and CSIR, India, respectively, for research fellowships. S.K.M. thanks CSIR (sanction no. 01(2369)/10/EMR-II), India, for financial support. M.M. thanks the German Science foundation for support within SFB 602 and SPP 1538, and S. Demeshko for SQUID measurements. D.S. and R.M. thank the Deutsche Forschungsgemeinschaft (DFG) Priority Programme 1178 and the Danish National Research Foundation (DNRF) funded Center for Materials Crystallography (CMC) for support, and the Land Niedersachsen for providing a fellowship in the Catalysis for Sustainable Synthesis (CaSuS) Ph.D. program. J.S.M., M.M, S.K.M. and D.S. thank the Göttingen-Kolkata ‘Open shell systems (G-KOSS)’ initiative for supporting the collaboration.

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Author notes

    • Karthik V. Raman
    •  & Alexander M. Kamerbeek

    Present address: IBM India Research Laboratory, Bangalore 560045, India (K.V.R.); Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands (A.M.K.).

    • Karthik V. Raman
    •  & Alexander M. Kamerbeek

    These authors contributed equally to this work.


  1. Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Massachusetts 02139, USA

    • Karthik V. Raman
    • , Alexander M. Kamerbeek
    •  & Jagadeesh S. Moodera
  2. Department of Materials Science and Engineering, Massachusetts Institute of Technology, Massachusetts 02139, USA

    • Karthik V. Raman
  3. Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER)-Kolkata, Mohanpur 741252, India

    • Arup Mukherjee
    • , Tamal K. Sen
    •  & Swadhin K. Mandal
  4. Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

    • Nicolae Atodiresei
    • , Vasile Caciuc
    •  & Stefan Blügel
  5. Theoretical Physics Division, Rudjer Boskovic Institute, PO Box 180, HR-10002 Zagreb, Croatia

    • Predrag Lazić
  6. Institut für Anorganische Chemie, Universität Göttingen, Göttingen 37077, Germany

    • Reent Michel
    •  & Dietmar Stalke
  7. I. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen 37077, Germany

    • Markus Münzenberg
  8. Physics Department, Massachusetts Institute of Technology, Massachusetts 02139, USA

    • Jagadeesh S. Moodera


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S.K.M., M.M. and J.S.M. designed the original research approach; A.M. and S.K.M. developed molecule synthesis; A.M.K., A.M., T.K.S., S.K.M., R.M. and D.S. performed material characterization; K.V.R. and A.M.K. prepared devices, performed transport experiments and analysed transport and magnetic characterization; N.A., P.L. and V.C. performed DFT calculations; K.V.R., A.M.K., N.A. and J.S.M. developed the organic spin-filter model; K.V.R., N.A. and J.S.M. developed the interface magnetic anisotropy model; K.V.R. coordinated collaboration; K.V.R., J.S.M. and M.M. wrote the manuscript; N.A., A.M.K., A.M. and S.K.M. provided the discussion and contributed to manuscript preparation. All authors discussed the experiments and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Karthik V. Raman or Nicolae Atodiresei or Swadhin K. Mandal or Jagadeesh S. Moodera.

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