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Room-temperature ferroelectric switching of spin-to-charge conversion in germanium telluride

Abstract

The development of spintronic devices has been limited by the poor compatibility between semiconductors and ferromagnetic sources of spin. The broken inversion symmetry of some semiconductors may allow for spin–charge interconversion, but its control by electric fields is volatile. This has led to interest in ferroelectric Rashba semiconductors, which combine semiconductivity, large spin–orbit coupling and non-volatility. Here we report room-temperature, non-volatile ferroelectric control of spin-to-charge conversion in epitaxial germanium telluride films. We show that ferroelectric switching by electrical gating is possible in germanium telluride, despite its high carrier density. We also show that spin-to-charge conversion has a similar magnitude to what is observed with platinum, but the charge current sign is controlled by the orientation of ferroelectric polarization. Comparison between theoretical and experimental data suggests that the inverse spin Hall effect plays a major role in switchable conversion.

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Fig. 1: Ferroelectric switching of GeTe by electrical gating and electric readout of the state.
Fig. 2: Resistive modulation in Ti/GeTe junctions.
Fig. 3: Ferroelectric control of SCC in GeTe investigated by SP-FMR.
Fig. 4: Theoretical evidence of switchable spin–charge interconversion in GeTe and prototypical device.

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

References

  1. 1.

    Zutic, I., Fabian, J. & Sarma, D. Spintronics: fundamentals and applications. Rev. Mod. Phys. 76, 323–410 (2004).

    Article  Google Scholar 

  2. 2.

    Awschalom, D. D. & Flatté, M. E. Challenges for semiconductor spintronics. Nat. Phys. 3, 153–159 (2007).

    Article  Google Scholar 

  3. 3.

    Schmidt, G., Ferrand, D., Molenkamp, L. W., Filip, A. T. & van Wees, B. J. Fundamental obstacle for electrical spin injection from a ferromagnetic metal into a diffusive semiconductor. Phys. Rev. B 62, R4790 (2000).

    Article  Google Scholar 

  4. 4.

    Dietl, T. A ten-year perspective on dilute magnetic semiconductors and oxides. Nat. Mater. 9, 965–974 (2010).

    Article  Google Scholar 

  5. 5.

    Tu, N. T., Hai, P. N., Anh, L. D. & Tanaka, M. High-temperature ferromagnetism in new n-type Fe-doped ferromagnetic semiconductor (In,Fe)Sb. Appl. Phys. Express 11, 063005 (2018).

    Article  Google Scholar 

  6. 6.

    Kato, Y. K., Myers, R. C., Gossard, A. C. & Awschalom, D. D. Observation of the spin Hall effect in semiconductors. Science 306, 1910–1913 (2004).

    Article  Google Scholar 

  7. 7.

    Ganichev, S. D. et al. Spin-galvanic effect. Nature 417, 153–156 (2002).

    Article  Google Scholar 

  8. 8.

    Awschalom, D. & Samarth, N. Spintronics without magnetism. Physics 2, 50 (2009).

    Article  Google Scholar 

  9. 9.

    Benítez, L. A. et al. Tunable room-temperature spin galvanic and spin Hall effects in van der Waals heterostructures. Nat. Mater. 19, 170–175 (2020).

    Article  Google Scholar 

  10. 10.

    Noël, P. et al. Non-volatile electric control of spin–charge conversion in a SrTiO3 Rashba system. Nature 580, 483–486 (2020).

    Article  Google Scholar 

  11. 11.

    Picozzi, S. Ferroelectric Rashba semiconductors as a novel class of multifunctional materials. Front. Phys. 2, 10 (2014).

    Article  Google Scholar 

  12. 12.

    Di Sante, D., Barone, P., Bertacco, R. & Picozzi, S. Electric control of the giant Rashba effect in bulk GeTe. Adv. Mater. 25, 509–513 (2013).

    Article  Google Scholar 

  13. 13.

    Liebmann, M. et al. Giant Rashba-type spin splitting in ferroelectric GeTe(111). Adv. Mater. 28, 560–565 (2016).

    Article  Google Scholar 

  14. 14.

    Rinaldi, C. et al. Ferroelectric control of the spin texture in GeTe. Nano Lett. 18, 2751–2758 (2018).

    Article  Google Scholar 

  15. 15.

    Manipatruni, S. et al. Scalable energy-efficient magnetoelectric spin–orbit logic. Nature 565, 35–42 (2019).

    Article  Google Scholar 

  16. 16.

    Guillet, T. et al. Magnetotransport in Bi2Se3 thin films epitaxially grown on Ge(111). AIP Adv. 8, 115125 (2018).

    Article  Google Scholar 

  17. 17.

    Zeng, Z. et al. Molecular beam epitaxial growth of Bi2Te3 and Sb2Te3 topological insulators on GaAs (111) substrates: a potential route to fabricate topological insulator p-n junction. AIP Adv. 3, 072112 (2013).

    Article  Google Scholar 

  18. 18.

    Sławińska, J. et al. Fe/GeTe(111) heterostructures as an avenue towards spintronics based on ferroelectric Rashba semiconductors. Phys. Rev. B 99, 075306 (2019).

    Article  Google Scholar 

  19. 19.

    Dery, H., Song, Y., Li, P. & Zutić, I. Silicon spin communication. Appl. Phys. Lett. 99, 082502 (2011).

    Article  Google Scholar 

  20. 20.

    Kolobov, A. V. et al. Ferroelectric switching in epitaxial GeTe films. APL Mater. 2, 066101 (2014).

    Article  Google Scholar 

  21. 21.

    Polking, M. J. et al. Ferroelectric order in individual nanometre-scale crystals. Nat. Mater. 11, 700–709 (2012).

    Article  Google Scholar 

  22. 22.

    Nukala, P. et al. Inverting polar domains via electrical pulsing in metallic germanium telluride. Nat. Commun. 8, 15033 (2017).

    Article  Google Scholar 

  23. 23.

    Kriegner, D. et al. Ferroelectric self-poling in GeTe films and crystals. Crystals 9, 335 (2019).

  24. 24.

    Wang, Y., Liu, X., Burton, J. D., Jaswal, S. S. & Tsymbal, E. Y. Ferroelectric instability under screened Coulomb interactions. Phys. Rev. Lett. 109, 247601 (2012).

    Article  Google Scholar 

  25. 25.

    Fei, Z. et al. Ferroelectric switching of a two-dimensional metal. Nature 560, 336–339 (2018).

    Article  Google Scholar 

  26. 26.

    Sharma, P. et al. A room-temperature ferroelectric semimetal. Sci. Adv. 5, eaax5080 (2019).

    Article  Google Scholar 

  27. 27.

    Rabe, K. M., Ahn, C. H. & Triscone, J.-M. Physics of Ferroelectrics: A Modern Perspective (Springer, 2007).

  28. 28.

    Baldrati, L. et al. Electrical switching of magnetization in the artificial multiferroic CoFeB/BaTiO3. Adv. Electron. Mater. 2, 1600085 (2016).

    Article  Google Scholar 

  29. 29.

    Park, J.-W. et al. Optical properties of pseudobinary GeTe, Ge2Sb2Te5, GeSb2Te4, GeSb4Te7, and Sb2Te3 from ellipsometry and density functional theory. Phys. Rev. B 80, 115209 (2009).

    Article  Google Scholar 

  30. 30.

    Yamada, H. et al. Giant electroresistance of super-tetragonal BiFeO3-based ferroelectric tunnel junctions. ACS Nano 7, 5385–5390 (2013).

    Article  Google Scholar 

  31. 31.

    Rinaldi, C. et al. Evidence for spin to charge conversion in GeTe(111). APL Mater. 4, 032501 (2016).

    Article  Google Scholar 

  32. 32.

    Chanthbouala, A. et al. A ferroelectric memristor. Nat. Mater. 11, 860–864 (2012).

    Article  Google Scholar 

  33. 33.

    Blom, P. W. M., Wolf, R. M., Cillessen, J. F. M. & Krijn, M. P. C. M. Ferroelectric Schottky diode. Phys. Rev. Lett. 73, 2107–2110 (1994).

    Article  Google Scholar 

  34. 34.

    Cantoni, M., Petti, D., Rinaldi, C. & Bertacco, R. Bandstructure line-up of epitaxial Fe/MgO/Ge heterostructures: a combined X-ray photoelectron spectroscopy and transport study. Appl. Phys. Lett. 98, 32103–32104 (2011).

    Article  Google Scholar 

  35. 35.

    Edwards, A. H. et al. Electronic structure of intrinsic defects in crystalline germanium telluride. Phys. Rev. B 73, 45210 (2006).

    Article  Google Scholar 

  36. 36.

    Michaelson, H. B. The work function of the elements and its periodicity. J. Appl. Phys. 48, 4729–4733 (1977).

    Article  Google Scholar 

  37. 37.

    Dey, M., Matin, M. A., Das, N. K. & Dey, M. Germanium telluride as a BSF material for high efficiency ultra-thin CdTe solar cell. In 2014 9th International Forum on Strategic Technology (IFOST) 334–338 (IEEE, 2014).

  38. 38.

    Tserkovnyak, Y., Brataas, A. & Bauer, G. E. W. Enhanced Gilbert damping in thin ferromagnetic films. Phys. Rev. Lett. 88, 117601 (2002).

    Article  Google Scholar 

  39. 39.

    Mosendz, O. et al. Detection and quantification of inverse spin Hall effect from spin pumping in permalloy/normal metal bilayers. Phys. Rev. B 82, 214403 (2010).

    Article  Google Scholar 

  40. 40.

    Rojas-Sánchez, J. C. et al. Spin pumping and inverse spin Hall effect in platinum: the essential role of spin-memory loss at metallic interfaces. Phys. Rev. Lett. 112, 106602 (2014).

    Article  Google Scholar 

  41. 41.

    Jungwirth, T., Wunderlich, J. & Olejník, K. Spin Hall effect devices. Nat. Mater. 11, 382–390 (2012).

    Article  Google Scholar 

  42. 42.

    Wang, H. et al. Spin Hall effect in prototype Rashba ferroelectrics GeTe and SnTe. npj Comput. Mater. 6, 7 (2020).

    Article  Google Scholar 

  43. 43.

    Sławińska, J. et al. Giant spin Hall effect in two-dimensional monochalcogenides. 2D Mater. 6, 025012 (2019).

    Article  Google Scholar 

  44. 44.

    Dushenko, S. et al. Tunable inverse spin Hall effect in nanometer-thick platinum films by ionic gating. Nat. Commun. 9, 3118 (2018).

    Article  Google Scholar 

  45. 45.

    Hoffmann, A. Spin Hall effects in metals. IEEE Trans. Magn. 49, 5172–5193 (2013).

    Article  Google Scholar 

  46. 46.

    Pham, V. T. et al. Spin–orbit magnetic state readout in scaled ferromagnetic/heavy metal nanostructures. Nat. Electron. 3, 309–315 (2020).

    Article  Google Scholar 

  47. 47.

    Lebedev, A. I. & Sluchinskaya, I. A. EXAFS study of the influence of impurities on the phase transition in GeTe. Ferroelectrics 298, 189–197 (2004).

    Article  Google Scholar 

  48. 48.

    Wang, R. et al. Toward truly single crystalline GeTe films: the relevance of the substrate surface. J. Phys. Chem. C 118, 29724–29730 (2014).

    Article  Google Scholar 

  49. 49.

    Boschker, J. E. et al. Surface reconstruction-induced coincidence lattice formation between two-dimensionally bonded materials and a three dimensionally bonded substrate. Nano Lett. 14, 3534–3538 (2014).

    Article  Google Scholar 

  50. 50.

    Boschker, J. E. et al. Electrical and optical properties of epitaxial binary and ternary GeTe-Sb2Te3 alloys. Sci. Rep. 8, 5889 (2018).

    Article  Google Scholar 

  51. 51.

    Giannozzi, P. et al. QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials. J. Phys. Condens. Matter 21, 395502 (2009).

    Article  Google Scholar 

  52. 52.

    Giannozzi, P. et al. Advanced capabilities for materials modelling with Quantum ESPRESSO. J. Phys. Condens. Matter 29, 465901 (2017).

    Article  Google Scholar 

  53. 53.

    Buongiorno Nardelli, M. et al. PAOFLOW: a utility to construct and operate on ab initio Hamiltonians from the projections of electronic wavefunctions on atomic orbital bases, including characterization of topological materials. Comput. Mater. Sci. 143, 462–472 (2018).

    Article  Google Scholar 

  54. 54.

    Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

    Article  Google Scholar 

  55. 55.

    Agapito, L. A., Curtarolo, S. & Buongiorno Nardelli, M. Reformulation of DFT + U as a pseudohybrid Hubbard density functional for accelerated materials discovery. Phys. Rev. X 5, 011006 (2015).

    Google Scholar 

  56. 56.

    Corso, A. D. Pseudopotentials periodic table: from H to Pu. Comput. Mater. Sci. 95, 337–350 (2014).

    Article  Google Scholar 

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Acknowledgements

C.R. acknowledges financial support by Fondazione Cariplo and Regione Lombardia (grant no. 2017-1622 (ECOS)). C.R. and S. Picozzi acknowledge support from the Italian Ministry of Universities and Research (MUR) under the PRIN programme, project no. 2017YCTB59 (towards ferroelectricity in two dimensions (TWEET)). M.B. acknowledges support from the European Research Council through the Advanced Grant ‘FRESCO’ no. 833973. J.S. acknowledges Rosalind Franklin Fellowship from the University of Groningen. We acknowledge financial support by ANR French National Research Agency Toprise (no. ANR-16-CE24-0017), ANR French National Research Agency OISO (no. ANR-17-CE24-0026), ANR French National Research Agency CONTRABASS (no. ANR-20-CE24-0023) and the Laboratoire d’excellence LANEF (no. ANR-10-LABX-51-01). We are grateful to the EPR facilities available at the National TGE RPE facilities (no. IR 3443) and to the High Performance Computing Center at the University of North Texas and the Texas Advanced Computing Center at the University of Texas, Austin. We acknowledge A. Brenac, J.-F. Jacquot, C. Lombard and S. Gambarelli for their help and advice on the FMR measurement setup. We are grateful to O. Klein, M. Jamet, F. Yu, T. Guillet, M. Guimarães, D. Di Sante, F. Pezzoli, V. Garcia and S. Fusil for helpful discussions. We thank C. Stemmler and S. Behnke for technical support with the MBE system. This work was partially performed at PoliFAB, the micro- and nanofabrication facility of the Politecnico di Milano.

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C.R. conceived the experiment and coordinated the research work with the support of R.B. S.C. and R.C. grew the GeTe/Si samples and performed the structural characterization. S.V., L.N, S. Petrò and A.N. fabricated the devices for electrical characterization and PFM experiments. S.V., C.R. and L.N. performed the PFM imaging. F.F. performed the measurements of switching speed. S. Petrò, C.R., S.V., D.P., E.A. and M. Cantoni grew the heterostructures for the SP experiments, while S.V., P.N., L.V. and J.-P.A. performed the experiments. J.S. performed the calculations with the support of M.B.N., M. Costa and S. Picozzi. C.R., M.B., J.S. and S.V. wrote the manuscript, with fundamental inputs from all the authors.

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Correspondence to Christian Rinaldi.

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Peer review information Nature Electronics thanks Chih-Huang Lai and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Figs. 1–4, Sections 1–6 and references.

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Varotto, S., Nessi, L., Cecchi, S. et al. Room-temperature ferroelectric switching of spin-to-charge conversion in germanium telluride. Nat Electron 4, 740–747 (2021). https://doi.org/10.1038/s41928-021-00653-2

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