Light-driven electrodynamics and demagnetization in FenGeTe2 (n = 3, 5) thin films
Source abstract
Abstract
Two-dimensional materials-based ultrafast spintronics are expected to surpass conventional data storage and manipulation technologies, that are now reaching their fundamental limits. The newly discovered van der Waals (VdW) magnets provide a new platform for ultrafast spintronics since their magnetic and electrical properties can be tuned by many external factors, such as strain, voltage, magnetic field, or light absorption for instance. Here, we report on the direct relationship between magnetic order and Terahertz (THz) electrodynamics in Fe n GeTe 2 ( n = 3, 5) (FGT) films after being illuminated by a femtosecond optical pulse, studying their ultrafast THz response as a function of the optical pump-THz probe temporal delay. In Fe 5 GeTe 2 , we find clear evidence that light-induced electronic excitations directly influence THz electrodynamics similarly to a demagnetization process, contrasting with the effects observed in Fe 3 GeTe 2 , which are characterized by a thermal energy transfer among electrons, magnons, and phonons. We address these effects as a function of the pump fluence and pump-probe delay, and by tuning the temperature across the magnetic ordering Curie temperature, highlighting the microscopic mechanisms describing the out-of-equilibrium evolution of the THz conductivity. Finally, we find evidence for the incoherent-coherent crossover predicted by the Kondo-Ising scenario in Fe 3 GeTe 2 and successfully simulate its light-driven electrodynamics through a three-temperature model. As indicated by these results, FGT surpasses conventional metals in terms of modulating their properties using an optical lever.
Source: openalex_inverted_index · Quality: baseline
Research context
OpenAlex topics: 2D Materials and Applications · Topological Materials and Phenomena · Heusler alloys: electronic and magnetic properties
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (71)
Show source-provided references
1. Tokura, Y., Yasuda, K. & Tsukazaki, A. Magnetic topological insulators. Nat. Rev. Phys. 1, 126–143 (2019).10.1038/s42254-018-0011-5 ↗
2. Chang, C.-Z. et al. Experimental observation of the quantum anomalous hall effect in a magnetic topological insulator. Science 340, 167–170 (2013).10.1126/science.1234414 ↗
3. Tomarchio, L. et al. Electrodynamics of MnBi2Te4 intrinsic magnetic topological insulators. NPG Asia Mater. 14, 82 (2022).10.1038/s41427-022-00429-w ↗
4. Knolle, J., Kovrizhin, D., Chalker, J. & Moessner, R. Dynamics of a two-dimensional quantum spin liquid: signatures of emergent Majorana fermions and fluxes. Phys. Rev. Lett. 112, 207203 (2014).10.1103/PhysRevLett.112.207203 ↗
5. Gong, C. et al. Discovery of intrinsic ferromagnetism in two-dimensional van der Waals crystals. Nature 546, 265–269 (2017).10.1038/nature22060 ↗
6. 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 ↗
7. Verchenko, V. Y., Tsirlin, A. A., Sobolev, A. V., Presniakov, I. A. & Shevelkov, A. V. Ferromagnetic order, strong magnetocrystalline anisotropy, and magnetocaloric effect in the layered Telluride Fe3GeTe2. Inorg. Chem. 54, 8598–8607 (2015).10.1021/acs.inorgchem.5b01260 ↗
8. May, A. F., Calder, S., Cantoni, C., Cao, H. & McGuire, M. A. Magnetic structure and phase stability of the van der Waals bonded ferromagnet Fe3-x GeTe2. Phys. Rev. B 93, 014411 (2016).10.1103/PhysRevB.93.014411 ↗
9. Deng, Y. et al. Gate-tunable room-temperature ferromagnetism in two-dimensional Fe3GeTe2. Nature 563, 94–99 (2018).10.1038/s41586-018-0626-9 ↗
10. Jiang, S., Li, L., Wang, Z., Mak, K. F. & Shan, J. Controlling magnetism in 2D CrI3 by electrostatic doping. Nat. Nanotechnol. 13, 549–553 (2018).10.1038/s41565-018-0135-x ↗
11. Tomarchio, L. et al. Low energy electrodynamics of CrI3 layered ferromagnet. Sci. Rep. 11, 23405 (2021).10.1038/s41598-021-02918-4 ↗
12. Tomarchio, L. et al. Phonon anharmonicity and spin-Phonon coupling in CrI3. Materials 16, 4909 (2023).10.3390/ma16144909 ↗
13. Huang, B. et al. Electrical control of 2D magnetism in bilayer CrI3. Nat. Nanotechnol. 13, 544–548 (2018).10.1038/s41565-018-0121-3 ↗
14. Yang, D. et al. Cr2Ge2Te6: High thermoelectric performance from layered structure with high symmetry. Chem. Mater. 28, 1611–1615 (2016).10.1021/acs.chemmater.5b04895 ↗
15. May, A. F. et al. Ferromagnetism near room temperature in the cleavable van der Waals Crystal Fe5GeTe2. ACS Nano 13, 4436–4442 (2019).10.1021/acsnano.8b09660 ↗
16. Fei, Z. et al. Two-dimensional itinerant ferromagnetism in atomically thin Fe3GeTe2. Nat. Mater. 17, 778–782 (2018).10.1038/s41563-018-0149-7 ↗
17. Wang, X. et al. Current-driven magnetization switching in a van der Waals ferromagnet Fe3GeTe2. Sci. Adv. 5, eaaw8904 (2019).10.1126/sciadv.aaw8904 ↗
18. Chen, X. et al. Generation and control of terahertz spin currents in topology-induced 2D ferromagnetic Fe3GeTe2∣Bi2Te3 Heterostructures. Adv. Mater. 34, 2106172 (2022).10.1002/adma.202106172 ↗
19. Li, Q. et al. Patterning-Induced ferromagnetism of Fe3GeTe2 van der Waals materials beyond room temperature. Nano Lett. 18, 5974–5980 (2018).10.1021/acs.nanolett.8b02806 ↗
20. Liu, S. et al. Wafer-scale two-dimensional ferromagnetic Fe3GeTe2 thin films grown by molecular beam epitaxy. npj 2D Mater. Appl. 1, 30 (2017).10.1038/s41699-017-0033-3 ↗
21. Tan, C. et al. Gate-controlled magnetic phase transition in a van der Waals magnet Fe5GeTe2. Nano Lett. 21, 5599–5605 (2021).10.1021/acs.nanolett.1c01108 ↗
22. Guillet, T. et al. Spin-Orbit torques and magnetization switching in (Bi,Sb)2Te3/Fe3GeTe2 heterostructures grown by molecular beam epitaxy. Nano Lett. acs.nanolett.3c03291 https://pubs.acs.org/doi/10.1021/acs.nanolett.3c03291 (2024).
23. Deiseroth, H., Aleksandrov, K., Reiner, C., Kienle, L. & Kremer, R. K. Fe3GeTe2 and Ni3GeTe2 - Two new layered transition-metal compounds: crystal structures, HRTEM investigations, and magnetic and electrical properties. Eur. J. Inorg. Chem. 2006, 1561–1567 (2006).10.1002/ejic.200501020 ↗
24. Chen, B. et al. Magnetic properties of layered itinerant electron ferromagnet Fe3GeTe2. J. Phys. Soc. Jpn. 82, 124711 (2013).10.7566/JPSJ.82.124711 ↗
25. Li, Z. et al. Magnetic critical behavior of the van der Waals Fe5GeTe2 crystal with near room temperature ferromagnetism. Sci. Rep. 10, 15345 (2020).10.1038/s41598-020-72203-3 ↗
26. Seo, J. et al. Nearly room temperature ferromagnetism in a magnetic metal-rich van der Waals metal. Sci. Adv. 6, eaay8912 (2020).10.1126/sciadv.aay8912 ↗
27. Ribeiro, M. et al. Large-scale epitaxy of two-dimensional van der Waals room-temperature ferromagnet Fe5GeTe2. npj 2D Mater. Appl. 6, 10 (2022).10.1038/s41699-022-00285-w ↗
28. Ohta, T. et al. Enhancement of coercive field in atomically-thin quenched Fe5GeTe2. Appl. Phys. Express 13, 043005 (2020).10.35848/1882-0786/ab7f18 ↗
29. Tan, C. et al. Hard magnetic properties in nanoflake van der Waals Fe3GeTe2. Nat. Commun. 9, 1554 (2018).10.1038/s41467-018-04018-w ↗
30. León-Brito, N., Bauer, E. D., Ronning, F., Thompson, J. D. & Movshovich, R. Magnetic microstructure and magnetic properties of uniaxial itinerant ferromagnet Fe3GeTe2. J. Appl. Phys. 120, 083903 (2016).10.1063/1.4961592 ↗
31. Kim, D. et al. Antiferromagnetic coupling of van der Waals ferromagnetic Fe3GeTe2. Nanotechnology 30, 245701 (2019).10.1088/1361-6528/ab0a37 ↗
32. Yi, J. et al. Competing antiferromagnetism in a quasi-2D itinerant ferromagnet: Fe3GeTe2. 2D Mater. 4, 011005 (2016).10.1088/2053-1583/4/1/011005 ↗
33. Birch, M. T. et al. History-dependent domain and skyrmion formation in 2D van der Waals magnet Fe3GeTe2. Nat. Commun. 13, 3035 (2022).10.1038/s41467-022-30740-7 ↗
34. Ding, B. et al. Observation of magnetic Skyrmion bubbles in a van der Waals Ferromagnet Fe3GeTe2. Nano Lett. 20, 868–873 (2020).10.1021/acs.nanolett.9b03453 ↗
35. Ohta, T. et al. Butterfly-shaped magnetoresistance in van der Waals ferromagnet Fe5GeTe2. AIP Adv. 11, 025014 (2021).10.1063/9.0000067 ↗
36. Lv, X. et al. Controllable topological magnetic transformations in the thickness-tunable van der Waals ferromagnet Fe5GeTe2. ACS Nano 16, 19319–19327 (2022).10.1021/acsnano.2c08844 ↗
37. Zhu, J.-X. et al. Electronic correlation and magnetism in the ferromagnetic metal Fe3GeTe2. Phys. Rev. B 93, 144404 (2016).10.1103/PhysRevB.93.144404 ↗
38. Huang, Y., Yao, X., Qi, F., Shen, W. & Cao, G. Anomalous resistivity upturn in the van der Waals ferromagnet Fe5GeTe2. Appl. Phys. Lett. 121, 162403 (2022).10.1063/5.0109735 ↗
39. Xu, X. et al. Signature for non-Stoner ferromagnetism in the van der Waals ferromagnet Fe3GeTe2. Phys. Rev. B 101, 201104 (2020).10.1103/PhysRevB.101.201104 ↗
40. Joe, M., Yang, U. & Lee, C. First-principles study of ferromagnetic metal Fe5GeTe2. Nano Mater. Sci. 1, 299–303 (2019).10.1016/j.nanoms.2019.09.009 ↗
41. Zhao, M. et al. Kondo holes in the two-dimensional itinerant ising ferromagnet Fe3GeTe2. Nano Lett. 21, 6117–6123 (2021).10.1021/acs.nanolett.1c01661 ↗
42. Zhang, Y. et al. Emergence of Kondo lattice behavior in a van der Waals itinerant ferromagnet, Fe3GeTe2. Sci. Adv. 4, eaao6791 (2018).10.1126/sciadv.aao6791 ↗
43. Onuki, Y., Furukawa, Y. & Komatsubara, T. Dense Kondo behavior in Cex La1−x Al2. J. Phys. Soc. Jpn. 53, 2734–2740 (1984).10.1143/JPSJ.53.2734 ↗
44. Gottwick, U. et al. Seebeck coefficient of heavy fermion compounds. J. Magn. Magn. Mater. 63-64, 341–343 (1987).10.1016/0304-8853(87)90605-6 ↗
45. Corasaniti, M. et al. Electronic correlations in the van der Waals ferromagnet Fe3GeTe2 revealed by its charge dynamics. Phys. Rev. B 102, 161109 (2020).10.1103/PhysRevB.102.161109 ↗
46. Du, L. et al. Lattice Dynamics, phonon chirality, and spin-phonon coupling in 2D Itinerant ferromagnet Fe3GeTe2. Adv. Funct. Mater. 29, 1904734 (2019).10.1002/adfm.201904734 ↗
47. Xu, J., Phelan, W. A. & Chien, C.-L. Large anomalous Nernst effect in a van der Waals ferromagnet Fe3GeTe2. Nano Lett. 19, 8250–8254 (2019).10.1021/acs.nanolett.9b03739 ↗
48. Kim, K. et al. Large anomalous Hall current induced by topological nodal lines in a ferromagnetic van der Waals semimetal. Nat. Mater. 17, 794–799 (2018).10.1038/s41563-018-0132-3 ↗
49. Suzuki, R., Gao, T., Nakayama, H. & Ando, K. Extrinsic anomalous Hall effect in van der Waals ferromagnet Fe5GeTe2. AIP Adv. 13, 055311 (2023).10.1063/5.0112456 ↗
50. Kuzmenko, A. B. Kramers-Kronig constrained variational analysis of optical spectra. Rev. Sci. Instrum. 76, 083108 (2005).10.1063/1.1979470 ↗
51. Heavens, O. S. Optical properties of thin films. Rep. Prog. Phys. 23, 1–65 (1960).10.1088/0034-4885/23/1/301 ↗
52. Del Fatti, N. et al. Nonequilibrium electron dynamics in noble metals. Phys. Rev. B 61, 16956–16966 (2000).10.1103/PhysRevB.61.16956 ↗
53. Giannetti, C. et al. Ultrafast optical spectroscopy of strongly correlated materials and high-temperature superconductors: a non-equilibrium approach. Adv. Phys. 65, 58–238 (2016).10.1080/00018732.2016.1194044 ↗
54. He, C. et al. Study of confined coherent acoustic phonon modes in a free-standing cubic GaN membrane by femtosecond spectroscopy. Appl. Phys. Lett. 107, 112105 (2015).10.1063/1.4931495 ↗
55. Liu, B. et al. Light-tunable ferromagnetism in atomically thin Fe3GeTe2 driven by Femtosecond laser pulse. Phys. Rev. Lett. 125, 267205 (2020).10.1103/PhysRevLett.125.267205 ↗
56. Demsar, J., Sarrao, J. L. & Taylor, A. J. Dynamics of photoexcited quasiparticles in heavy electron compounds. J. Phys.: Condens. Matter 18, R281–R314 (2006).
57. Vaterlaus, A., Beutler, T. & Meier, F. Spin-lattice relaxation time of ferromagnetic gadolinium determined with time-resolved spin-polarized photoemission. Phys. Rev. Lett. 67, 3314–3317 (1991).10.1103/PhysRevLett.67.3314 ↗
58. Si, M. S. & Zhang, G. P. Resolving photon-shortage mystery in femtosecond magnetism. J. Phys.: Condens. Matter 22, 076005 (2010).
59. Zhang, T. et al. Laser-induced magnetization dynamics in a van der Waals ferromagnetic Cr2Ge2Te6 nanoflake. Appl. Phys. Lett. 116, 223103 (2020).10.1063/5.0006080 ↗
60. Koopmans, B. et al. Explaining the paradoxical diversity of ultrafast laser-induced demagnetization. Nat. Mater. 9, 259–265 (2010).10.1038/nmat2593 ↗
61. Carva, K., Baláž, P. & Radu, I. Laser-Induced Ultrafast Magnetic Phenomena. In Handbook of Magnetic Materials, vol. 26, 291–463 (Elsevier, 2017). https://linkinghub.elsevier.com/retrieve/pii/S1567271917300045.10.1016/bs.hmm.2017.09.003 ↗
62. Beaurepaire, E. et al. Coherent terahertz emission from ferromagnetic films excited by femtosecond laser pulses. Appl. Phys. Lett. 84, 3465–3467 (2004).10.1063/1.1737467 ↗
63. Scheid, P., Remy, Q., Lebègue, S., Malinowski, G. & Mangin, S. Light induced ultrafast magnetization dynamics in metallic compounds. J. Magn. Magn. Mater. 560, 169596 (2022).10.1016/j.jmmm.2022.169596 ↗
64. Scheid, P., Malinowski, G., Mangin, S. & Lebègue, S. Ab initio study of electronic temperature effects on magnetic materials properties. Phys. Rev. B 99, 174415 (2019).10.1103/PhysRevB.99.174415 ↗
65. Essert, S. & Schneider, H. C. Electron-phonon scattering dynamics in ferromagnetic metals and their influence on ultrafast demagnetization processes. Phys. Rev. B 84, 224405 (2011).10.1103/PhysRevB.84.224405 ↗
66. Beaurepaire, E., Merle, J.-C., Daunois, A. & Bigot, J.-Y. Ultrafast spin dynamics in ferromagnetic nickel. Phys. Rev. Lett. 76, 4250–4253 (1996).10.1103/PhysRevLett.76.4250 ↗
67. Schmidt, A. B. et al. Ultrafast Magnon generation in an Fe film on Cu(100). Phys. Rev. Lett. 105, 197401 (2010).10.1103/PhysRevLett.105.197401 ↗
68. Stanciu, C. D. et al. All-optical magnetic recording with circularly polarized light. Phys. Rev. Lett. 99, 047601 (2007).10.1103/PhysRevLett.99.047601 ↗
69. Roth, T. et al. Temperature dependence of laser-induced demagnetization in Ni: A key for identifying the underlying mechanism. Phys. Rev. X 2, 021006 (2012).
70. Lichtenberg, T. et al. Anisotropic laser-pulse-induced magnetization dynamics in van der Waals magnet Fe3GeTe2. 2D Mater. 10, 015008 (2023).10.1088/2053-1583/ac9dab ↗
71. Coleman, P. Heavy Fermions and the Kondo Lattice: a 21st Century Perspective http://arxiv.org/abs/1509.05769 (2015).