journal article·2022-03-14Open access

Two-dimensional ferromagnetism detected by proximity-coupled quantum Hall effect of graphene

Tuan Khanh Chau, Sung Ju Hong, Haeyong Kang, Dongseok Suh

npj Quantum Materials· Volume 7· Issue 1

Abstract

Abstract The recent discovery of a two-dimensional van der Waals magnet has paved the way for an enhanced understanding of two-dimensional magnetic systems. The development of appropriate heterostructures in this emerging class of materials is required as the next step towards applications. Here, we report on the electrical transport in monolayer graphene coupled with the two-dimensional ferromagnet Cr2Ge2Te6 (CGT). Graphene that forms an interface with CGT is electron-doped owing to charge transfer. The temperature-dependent resistance of graphene/CGT undergoes a nontrivial sudden change near the Curie temperature (Tc) of CGT. Apart from this, the behavior of various transport parameters also differs before and after Tc. Moreover, the contribution of the magnetization of CGT to the enhanced magnetic flux density leads to the critical evolution of the quantum Hall state. These results imply that graphene in the graphene/CGT hybrid structure can be utilized to electrically monitor the magnetic phase transition of the adjacent CGT layer.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Graphene research and applications · 2D Materials and Applications · Quantum and electron transport phenomena

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (51)

Show source-provided references
1. Dean, C. R. et al. Boron nitride substrates for high-quality graphene electronics. Nat. Nanotechnol. 5, 722–726 (2010).10.1038/nnano.2010.172 ↗
2. Du, X. et al. Fractional quantum Hall effect and insulating phase of Dirac electrons in graphene. Nature 462, 192–195 (2009).10.1038/nature08522 ↗
3. Bolotin, K. I. et al. Observation of the fractional quantum Hall effect in graphene. Nature 462, 196–199 (2009).10.1038/nature08582 ↗
4. Cao, Y. et al. Unconventional superconductivity in magic-angle graphene superlattices. Nature 556, 43–50 (2018).10.1038/nature26160 ↗
5. Cao, Y. et al. Correlated insulator behaviour at half-filling in magic-angle graphene superlattices. Nature 556, 80–84 (2018).10.1038/nature26154 ↗
6. Yankowitz, M. et al. Emergence of superlattice Dirac points in graphene on hexagonal boron nitride. Nat. Phys. 8, 382–386 (2012).10.1038/nphys2272 ↗
7. Ponomarenko, L. A. et al. Cloning of Dirac fermions in graphene superlattices. Nature 497, 594–594 (2013).10.1038/nature12187 ↗
8. Dean, C. R. et al. Hofstadter’s butterfly and the fractal quantum Hall effect in moiré superlattices. Nature 497, 598–602 (2013).10.1038/nature12186 ↗
9. Schmidt, H., Rode, J. C., Smirnov, D. & Haug, R. J. Superlattice structures in twisted bilayers of folded graphene. Nat. Commun. 5, 5742 (2014).10.1038/ncomms6742 ↗
10. Cao, Y. et al. Superlattice-induced insulating states and valley-protected orbits in twisted bilayer graphene. Phys. Rev. Lett. 117, 116804 (2016).10.1103/PhysRevLett.117.116804 ↗
11. Kim, Y. et al. Charge inversion and topological phase transition at a twist angle induced van Hove singularity of bilayer graphene. Nano Lett. 16, 5053–5059 (2016).10.1021/acs.nanolett.6b01906 ↗
12. Park, N. et al. Ferroelectric single-crystal gated graphene/hexagonal-BN/ferroelectric field-effect transistor. ACS Nano 9, 10729–10736 (2015).10.1021/acsnano.5b04339 ↗
13. Wei, P. et al. Strong interfacial exchange field in the graphene/EuS heterostructure. Nat. Mater. 15, 711–716 (2016).10.1038/nmat4603 ↗
14. Sakai, S. et al. Proximity-induced spin polarization of graphene in contact with half-metallic manganite. ACS Nano 10, 7532–7541 (2016).10.1021/acsnano.6b02424 ↗
15. Tang, C. et al. Approaching quantum anomalous Hall effect in proximity-coupled YIG/graphene/h-BN sandwich structure. APL Mater. 6, 026401 (2017).10.1063/1.5001318 ↗
16. Song, H.-D. et al. Electrical control of magnetic proximity effect in a graphene/multiferroic heterostructure. Appl. Phys. Lett. 113, 183101 (2018).10.1063/1.5055811 ↗
17. Song, H.-D. et al. Asymmetric modulation on exchange field in a graphene/BiFeO3 heterostructure by external magnetic field. Nano Lett. 18, 2435–2441 (2018).10.1021/acs.nanolett.7b05480 ↗
18. Wu, Y.-F. et al. Magnetic proximity effect in graphene coupled to a BiFeO3 nanoplate. Phys. Rev. B 95, 195426 (2017).10.1103/PhysRevB.95.195426 ↗
19. Wang, Z. et al. Proximity-induced ferromagnetism in graphene revealed by the anomalous Hall effect. Phys. Rev. Lett. 114, 016603 (2015).10.1103/PhysRevLett.114.016603 ↗
20. Song, G., Ranjbar, M., Daughton, D. R. & Kiehl, R. A. Nanoparticle-induced anomalous Hall effect in graphene. Nano Lett. 19, 7112–7118 (2019).10.1021/acs.nanolett.9b02643 ↗
21. Averyanov, D. V. et al. High-temperature magnetism in graphene induced by proximity to EuO. ACS Appl. Mater. Interfaces 10, 20767–20774 (2018).10.1021/acsami.8b04289 ↗
22. Cheng, G. et al. Graphene in proximity to magnetic insulating LaMnO3. Appl. Phys. Lett. 105, 133111 (2014).10.1063/1.4897224 ↗
23. Wu, Y. et al. Large exchange splitting in monolayer graphene magnetized by an antiferromagnet. Nat. Electron. 3, 604–611 (2020).10.1038/s41928-020-0458-0 ↗
24. Mermin, N. D. & Wagner, H. Absence of ferromagnetism or antiferromagnetism in one- or two-dimensional isotropic Heisenberg models. Phys. Rev. Lett. 17, 1133–1136 (1966).10.1103/PhysRevLett.17.1133 ↗
25. Gong, C. et al. Discovery of intrinsic ferromagnetism in two-dimensional van der Waals crystals. Nature 546, 265–269 (2017).10.1038/nature22060 ↗
26. Huang, B. et al. Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit. Nature 546, 270–273 (2017).10.1038/nature22391 ↗
27. Deng, Y. et al. Gate-tunable room-temperature ferromagnetism in two-dimensional Fe3GeTe2. Nature 563, 94–99 (2018).10.1038/s41586-018-0626-9 ↗
28. Burch, K. S., Mandrus, D. & Park, J.-G. Magnetism in two-dimensional van der Waals materials. Nature 563, 47–52 (2018).10.1038/s41586-018-0631-z ↗
29. Gong, C. & Zhang, X. Two-dimensional magnetic crystals and emergent heterostructure devices. Science 363, eaav4450 (2019).10.1126/science.aav4450 ↗
30. Gibertini, M., Koperski, M., Morpurgo, A. F. & Novoselov, K. S. Magnetic 2D materials and heterostructures. Nat. Nanotechnol. 14, 408–419 (2019).10.1038/s41565-019-0438-6 ↗
31. Haugen, H., Huertas-Hernando, D. & Brataas, A. Spin transport in proximity-induced ferromagnetic graphene. Phys. Rev. B 77, 115406 (2008).10.1103/PhysRevB.77.115406 ↗
32. Singh, S. et al. Strong modulation of spin Currents in bilayer graphene by static and fluctuating proximity exchange fields. Phys. Rev. Lett. 118, 187201 (2017).10.1103/PhysRevLett.118.187201 ↗
33. Leutenantsmeyer, J. C., Kaverzin, A. A., Wojtaszek, M. & van Wees, B. J. Proximity induced room temperature ferromagnetism in graphene probed with spin currents. 2D Mater. 4, 014001 (2016).10.1088/2053-1583/4/1/014001 ↗
34. Zollner, K., Gmitra, M. & Fabian, J. Electrically tunable exchange splitting in bilayer graphene on monolayer Cr2X2Te6 with X = Ge, Si, and Sn. N. J. Phys. 20, 073007 (2018).10.1088/1367-2630/aace51 ↗
35. Karpiak, B. et al. Magnetic proximity in a van der Waals heterostructure of magnetic insulator and graphene. 2D Mater. 7, 015026 (2019).10.1088/2053-1583/ab5915 ↗
36. Xing, W. et al. Electric field effect in multilayer Cr2Ge2Te6: a ferromagnetic 2D material. 2D Mater. 4, 024009 (2017).10.1088/2053-1583/aa7034 ↗
37. Wang, Z. et al. Electric-field control of magnetism in a few-layered van der Waals ferromagnetic semiconductor. Nat. Nanotechnol. 13, 554–559 (2018).10.1038/s41565-018-0186-z ↗
38. Escolar, J. et al. Anisotropic magnetoconductance and Coulomb blockade in defect engineered Cr2Ge2Te6 van der Waals heterostructures. Phys. Rev. B 100, 054420 (2019).10.1103/PhysRevB.100.054420 ↗
39. Ji, H. et al. A ferromagnetic insulating substrate for the epitaxial growth of topological insulators. J. Appl. Phys. 114, 114907 (2013).10.1063/1.4822092 ↗
40. Hao, Z. et al. Atomic scale electronic structure of the ferromagnetic semiconductor Cr2Ge2Te6. Sci. Bull. 63, 825–830 (2018).10.1016/j.scib.2018.05.034 ↗
41. Heo, J. et al. Nonmonotonic temperature dependent transport in graphene grown by chemical vapor deposition. Phys. Rev. B 84, 035421 (2011).10.1103/PhysRevB.84.035421 ↗
42. Özyilmaz, B. et al. Electronic transport and quantum Hall effect in bipolar graphene p-n-p junctions. Phys. Rev. Lett. 99, 166804 (2007).10.1103/PhysRevLett.99.166804 ↗
43. Yamada, T. et al. Field emission characteristics from graphene on hexagonal boron nitride. Appl. Phys. Lett. 104, 221603 (2014).10.1063/1.4881718 ↗
44. Kaushik, N. et al. Reversible hysteresis inversion in MoS2 field effect transistors. npj 2D Mater. Appl. 1, 34 (2017).10.1038/s41699-017-0038-y ↗
45. Zhang, Y., Tan, Y.-W., Stormer, H. L. & Kim, P. Experimental observation of the quantum Hall effect and Berry’s phase in graphene. Nature 438, 201–204 (2005).10.1038/nature04235 ↗
46. Giesbers, A. J. M. et al. Quantum-Hall activation gaps in graphene. Phys. Rev. Lett. 99, 206803 (2007).10.1103/PhysRevLett.99.206803 ↗
47. Wang, H. et al. Hysteresis of electronic transport in graphene transistors. ACS Nano 4, 7221–7228 (2010).10.1021/nn101950n ↗
48. Yoo, J. S., Park, Y. W., Skákalová, V. & Roth, S. Shubnikov–de Haas and Aharonov Bohm effects in a graphene nanoring structure. Appl. Phys. Lett. 96, 143112 (2010).10.1063/1.3380616 ↗
49. Barthold, P., Lüdtke, T., Schmidt, H. & Haug, R. J. Low-temperature hysteresis in the field effect of bilayer graphene. N. J. Phys. 13, 043020 (2011).10.1088/1367-2630/13/4/043020 ↗
50. Kang, H. et al. Quantum Hall conductance of graphene combined with charge-trap memory operation. Nanotechnology 26, 345202 (2015).10.1088/0957-4484/26/34/345202 ↗
51. Mohrmann, J., Watanabe, K., Taniguchi, T. & Danneau, R. Persistent hysteresis in graphene-mica van der Waals heterostructures. Nanotechnology 26, 015202 (2014).10.1088/0957-4484/26/1/015202 ↗