Because of their ultrafast intrinsic dynamics and robustness against stray fields, antiferromagnetic insulators1,2,3 are promising candidates for spintronic components. Therefore, long-distance, low-dissipation spin transport and electrical manipulation of antiferromagnetic order are key research goals in antiferromagnetic spintronics. Here, we report experimental evidence of robust spin transport through an antiferromagnetic insulator, in our case the gate-controlled state that appears in charge-neutral graphene in a magnetic field4,5,6. Utilizing quantum Hall edge states as spin-dependent injectors and detectors, we observe large, non-local electrical signals across charge-neutral channels that are up to 5 μm long. The dependence of the signal on magnetic field, temperature and filling factor is consistent with spin superfluidity1,2,4,7,8,9,10 as the spin-transport mechanism. This work demonstrates the utility of graphene in the quantum Hall regime as a powerful model system for fundamental studies in antiferromagnetic spintronics.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $15.58 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Baltz, V. et al. Antiferromagnetism: the next flagship magnetic order for spintronics? Rev. Mod. Phys. 90, 015005 (2018).
Jungwirth, T., Marti, X., Wadley, P. & Wunderlich, J. Antiferromagnetic spintronics. Nat. Nanotech. 11, 231–241 (2016).
Wadley, P. et al. Electrical switching of an antiferromagnet. Science 351, 587–590 (2016).
Takei, S., Yacoby, A., Halperin, B. I. & Tserkovnyak, Y. Spin superfluidity in the ν=0 quantum Hall state of graphene. Phys. Rev. Lett. 116, 216801 (2016).
Young, A. F. et al. Tunable symmetry breaking and helical edge transport in a graphene quantum spin Hall state. Nature 505, 528–532 (2014).
Kharitonov, M. Edge excitations of the canted antiferromagnetic phase of the ν=0 quantum Hall state in graphene: A simplified analysis. Phys. Rev. B 86, 075450 (2012).
Takei, S., Moriyama, T., Ono, T. & Tserkovnyak, Y. Antiferromagnet-mediated spin transfer between a metal and a ferromagnet. Phys. Rev. B 92, 020409 (2015).
Takei, S., Halperin, B. I., Yacoby, A. & Tserkovnyak, Y. Superfluid spin transport through antiferromagnetic insulators. Phys. Rev. B 90, 094408 (2014).
Konig, J., Bonsager, M. C. & MacDonald, A. H. Dissipationless spin transport in thin film ferromagnets. Phys. Rev. Lett. 87, 187202 (2001).
Qaiumzadeh, A., Skarsvåg, H., Holmqvist, C. & Brataas, A. Spin superfluidity in biaxial antiferromagnetic insulators. Phys. Rev. Lett. 118, 137201 (2017).
Tsoi, M. et al. Generation and detection of phase-coherent current-driven magnons in magnetic multilayers. Nature 406, 46–48 (2000).
Chumak, A. V., Vasyuchka, V. I., Serga, A. A. & Hillebrands, B. Magnon spintronics. Nat. Phys. 11, 453–461 (2015).
Núñez, A. S., Duine, R. A., Haney, P. & MacDonald, A. H. Theory of spin torques and giant magnetoresistance in antiferromagnetic metals. Phys. Rev. B 73, 214426 (2006).
Wang, H. L., Du, C. H., Hammel, P. C. & Yang, F. Y. Antiferromagnonic spin transport from Y3Fe5O12 into NiO. Phys. Rev. Lett. 113, 097202 (2014).
Hahn, C. et al. Conduction of spin currents through insulating antiferromagnetic oxides. Europhys. Lett. 108, 57005 (2014).
Moriyama, T. et al. Anti-damping spin transfer torque through epitaxial nickel oxide. Appl. Phys. Lett. 106, 162406 (2015).
Wang, H. L., Du, C. H., Hammel, P. C. & Yang, F. Y. Spin transport in antiferromagnetic insulators mediated by magnetic correlations. Phys. Rev. B 91, 220410 (2015).
Nomura, K. & MacDonald, A. H. Quantum Hall ferromagnetism in graphene. Phys. Rev. Lett. 96, 256602 (2006).
Alicea, J. & Fisher, M. P. A. Graphene integer quantum Hall effect in the ferromagnetic and paramagnetic regimes. Phys. Rev. B 74, 075422 (2006).
Abanin, D. A. et al. Dissipative quantum Hall effect in graphene near the Dirac point. Phys. Rev. Lett. 98, 196806 (2007).
Goerbig, M. O., Moessner, R. & Doucot, B. Electron interactions in graphene in a strong magnetic field. Phys. Rev. B 74, 161407 (2006).
Kim, S., Lee, K. & Tutuc, E. Spin-polarized to valley-polarized transition in graphene bilayers at ν=0 in high magnetic fields. Phys. Rev. Lett. 107, 016803 (2009).
Jiang, Z., Zhang, Y., Stormer, H. L. & Kim, P. Quantum Hall states near the charge-neutral Dirac point in graphene. Phys. Rev. Lett. 99, 106802 (2007).
Checkelsky, J. G., Li, L. & Ong, N. P. Zero-energy state in graphene in a high magnetic field. Phys. Rev. Lett. 100, 206801 (2008).
Checkelsky, J. G., Li, L. & Ong, N. P. Divergent resistance at the Dirac point in graphene: Evidence for a transition in a high magnetic field. Phys. Rev. B 79, 115434 (2009).
Giesbers, A. J. M. et al. Gap opening in the zeroth Landau level of graphene. Phys. Rev. B 80, 201403 (2009).
Zhao, Y., Cadden-Zimansky, P., Jiang, Z. & Kim, P. Symmetry breaking in the zero-energy Landau level in bilayer graphene. Phys. Rev. Lett. 104, 066801 (2010).
Young, A. F. et al. Spin and valley quantum Hall ferromagnetism in graphene. Nat. Phys. 8, 550–556 (2012).
Zhang, Y. et al. Landau-level splitting in graphene in high magnetic fields. Phys. Rev. Lett. 96, 136806 (2006).
Sun, Q.-f & Xie, X. C. Spin-polarized ν=0 state of graphene: A spin superconductor. Phys. Rev. B 87, 245427 (2013).
Abanin, D. A., Lee, P. A. & Levitov, L. S. Spin-filtered edge states and quantum Hall effect in graphene. Phys. Rev. Lett. 96, 176803 (2006).
Takei, S. & Tserkovnyak, Y. Superfluid spin transport through easy-plane ferromagnetic insulators. Phys. Rev. Lett. 112, 227201 (2014).
Wu, F., Sodemann, I., Araki, Y., MacDonald, A. H. & Jolicoeur, T. SO(5) symmetry in the quantum Hall effect in graphene. Phys. Rev. B 90, 235432 (2014).
Chklovskii, D. B., Shklovskii, B. I. & Glazman, L. I. Electrostatics of edge channels. Phys. Rev. B 46, 4026–4034 (1992).
Abanin, D. A. et al. Giant nonlocality near the Dirac point in graphene. Science 332, 328–330 (2011).
Studer, M. & Folk, J. A. Origins of nonlocality near the neutrality point in graphene. Phys. Rev. Lett. 112, 116601 (2014).
Chen, H., Kent, A. D., MacDonald, A. H. & Sodemann, I. Nonlocal transport mediated by spin supercurrents. Phys. Rev. B 90, 220401 (2014).
Zhao, Y. et al. Experimental investigation of temperature-dependent Gilbert damping in permalloy thin films. Sci. Rep. 6, 22890 (2016).
Johansen, Ø. & Linder, J. Current driven spin–orbit torque oscillator: ferromagnetic and antiferromagnetic coupling. Sci. Rep. 6, 33845 (2016).
Kim, T. H., Grünberg, P., Han, S. H. & Cho, B. Ultrafast spin dynamics and switching via spin transfer torque in antiferromagnets with weak ferromagnetism. Sci. Rep. 6, 35077 (2016).
Yankowitz, M. et al. Emergence of superlattice Dirac points in graphene on hexagonal boron nitride. Nat. Phys. 8, 382–386 (2012).
Ozyilmaz, B. et al. Electronic transport and quantum Hall effect in bipolar graphene p–n–p junctions. Phys. Rev. Lett. 99, 166804 (2007).
Wei, D. S. et al. Electrical generation and detection of spin waves in a quantum Hall ferromagnet. Preprint at https://arXiv.org/abs/1801.08534 (2018).
Wang, L. et al. One-dimensional electrical contact to a two-dimensional material. Science 342, 614–617 (2013).
We thank H. Chen for helpful discussions. The work is supported by SHINES, which is an Energy Frontier Research Center funded by the Department of Energy (DOE) Basic Energy Sciences (BES) under Award #SC0012670. S.C. is supported by DOE BES under award ER 46940-DE-SC0010597 to study the quantum Hall effect in graphene. A.H.M. acknowledges partial support by the Welch Foundation under grant TBF1473. Part of this work was performed at the NHMFL, which is supported by NSF/DMR-0654118, the State of Florida, and the DOE. Growth of hBN crystals was supported by the Elemental Strategy Initiative conducted by the MEXT, Japan and a Grant-in-Aid for Scientific Research on Innovative Areas ‘Science of Atomic Layers’ from the Japan Society for the Promotion of Science (JSPS).
Supplementary Figures 1–5
Movie demonstrating spin transport