AI Chat Paper
Note: Please note that the following content is generated by AMiner AI. SciOpen does not take any responsibility related to this content.
{{lang === 'zh_CN' ? '文章概述' : 'Summary'}}
{{lang === 'en_US' ? '中' : 'Eng'}}
Chat more with AI
Powered by AMiner. Clicking this button will take you away from SciOpen.
Home Nano Research Article
Article Link
Cite
EndNote(RIS) BibTeX
Collect
Submit Manuscript
Show Outline
Outline
Show full outline
Hide outline
Outline
Show full outline
Hide outline
Research Article

Enhanced valley polarization in WSe2/YIG heterostructures via interfacial magnetic exchange effect

Haihong Zheng1,2, Biao Wu1,2, Chang-Tian Wang3,4, Shaofei Li1, Jun He1, Zongwen Liu5,6, Jian-Tao Wang3,4,7, Guoqiang Yu3,7, Ji-An Duan2, Yanping Liu1,2,8 ( )
School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, Changsha 410083, China
State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Central South University, Changsha 410083, China
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
School of Chemical and Biomolecular Engineering, The University of Sydney, NSW 2006, Australia
The University of Sydney Nano Institute, The University of Sydney, NSW 2006, Australia
Songshan Lake Materials Laboratory, Dongguan 523808, China
Shenzhen Research Institute of Central South University, Shenzhen 518057, China
Show Author Information

Graphical Abstract

Our study reveals the modulation of valley polarization through the interfacial magnetic exchange of magnetic substrates. The experimental results indicate that the presence of a magnetic substrate, in conjunction with an applied magnetic field, can significantly enhance valley polarization. This significant finding opens up new possibilities for controlling and regulating valley polarization and highlights the potential of magnetic heterojunctions in magneto-optoelectronics applications.

Abstract

Exploiting the valley degrees of freedom as information carriers provides new opportunities for the development of valleytronics. Monolayer transition metal dichalcogenides (TMDs) with broken space-inversion symmetry exhibit emerging valley pseudospins, making them ideal platforms for studying valley electronics. However, intervalley scattering of different energy valleys limits the achievable degree of valley polarization. Here, we constructed WSe2/yttrium iron garnet (YIG) heterostructures and demonstrated that the interfacial magnetic exchange effect on the YIG magnetic substrate can enhance valley polarization by up to 63%, significantly higher than that of a monolayer WSe2 on SiO2/Si (11%). Additionally, multiple sharp exciton peaks appear in the WSe2/YIG heterostructures due to the strong magnetic proximity effect at the magnetic–substrate interface that enhances exciton emission efficiency. Moreover, under the effect of external magnetic field, the magnetic direction of the magnetic substrate enhances valley polarization, further demonstrating that the magnetic proximity effect regulates valley polarization. Our results provide a new way to regulate valley polarization and demonstrate the promising application of magnetic heterojunctions in magneto-optoelectronics.

Keywords

magnetic exchange effectvalley polarizationtwo-dimensionalvalleytronicsmagnetic substrate

References

[1]

Zhang, L. F.; Jiang, J.; Multunas, C.; Ming, C.; Chen, Z. Z.; Hu, Y.; Lu, Z. H.; Pendse, S.; Jia, R.; Chandra, M. et al. Room-temperature electrically switchable spin–valley coupling in a van der Waals ferroelectric halide perovskite with persistent spin helix. Nat. Photon. 2022, 16, 529–537.
Crossref Google Scholar
[2]

Wu, B.; Zheng, H. H.; Li, S. F.; Wang, C. T.; Ding, J. N.; He, J.; Liu, Z. W.; Wang, J. T.; Liu, Y. P. Effect of layered-coupling in twisted WSe2 moiré superlattices. Nano Res. 2023, 16, 3435–3442.
Crossref Google Scholar
[3]

Wang, Z. F.; Shan, J.; Mak, K. F. Valley- and spin-polarized Landau levels in monolayer WSe2. Nat. Nanotechnol. 2017, 12, 144–149.
Crossref Google Scholar
[4]

Wu, B.; Zheng, H. H.; Ding, J. N.; Wang, Y. P.; Liu, Z. W.; Liu, Y. P. Observation of interlayer excitons in trilayer type-II transition metal dichalcogenide heterostructures. Nano Res. 2022, 15, 9588–9594.
Crossref Google Scholar
[5]

Robert, C.; Park, S.; Cadiz, F.; Lombez, L.; Ren, L.; Tornatzky, H.; Rowe, A.; Paget, D.; Sirotti, F.; Yang, M. et al. Spin/valley pumping of resident electrons in WSe2 and WS2 monolayers. Nat. Commun. 2021, 12, 5455.
Crossref Google Scholar
[6]

Zhao, S. W.; Li, X. X.; Dong, B. J.; Wang, H. D.; Wang, H. W.; Zhang, Y. P.; Han, Z.; Zhang, H. Valley manipulation in monolayer transition metal dichalcogenides and their hybrid systems: Status and challenges. Rep. Prog. Phys. 2021, 84, 026401.
Crossref Google Scholar
[7]

Zhang, H. S.; Yang, W. J.; Ning, Y. H.; Xu, X. H. Abundant valley-polarized states in two-dimensional ferromagnetic van der Waals heterostructures. Phys. Rev. B 2020, 101, 205404.
Crossref Google Scholar
[8]

Wu, B.; Zheng, H. H.; Li, S. F.; Ding, J. N.; He, J.; Liu, Z. W.; Liu, Y. P. Enhanced interlayer neutral excitons and trions in MoSe2/MoS2/MoSe2 trilayer heterostructure. Nano Res. 2022, 15, 5640–5645.
Crossref Google Scholar
[9]

Cao, T.; Wang, G.; Han, W. P.; Ye, H. Q.; Zhu, C. R.; Shi, J. R.; Niu, Q.; Tan, P. H.; Wang, E. G.; Liu, B. L. et al. Valley-selective circular dichroism of monolayer molybdenum disulphide. Nat. Commun. 2012, 3, 887.
Crossref Google Scholar
[10]

Wu, B.; Wang, Y. P.; Zhong, J. H.; Zeng, C.; Madoune, Y.; Zhu, W. T.; Liu, Z. W.; Liu, Y. P. Observation of double indirect interlayer exciton in MoSe2/WSe2 heterostructure. Nano Res. 2022, 15, 2661–2666.
Crossref Google Scholar
[11]

Yuan, H. T.; Wang, X. Q.; Lian, B.; Zhang, H. J.; Fang, X. F.; Shen, B.; Xu, G.; Xu, Y.; Zhang, S. C.; Hwang, H. Y. et al. Generation and electric control of spin–valley-coupled circular photogalvanic current in WSe2. Nat. Nanotechnol. 2014, 9, 851–857.
Crossref Google Scholar
[12]

Rasmita, A.; Gao, W. B. Opto-valleytronics in the 2D van der Waals heterostructure. Nano Res. 2021, 14, 1901–1911.
Crossref Google Scholar
[13]

Xu, X. D.; Yao, W.; Xiao, D.; Heinz, T. F. Spin and pseudospins in layered transition metal dichalcogenides. Nat. Phys. 2014, 10, 343–350.
Crossref Google Scholar
[14]

Li, S. F.; Zheng, H. H.; Ding, J. N.; Wu, B.; He, J.; Liu, Z. W.; Liu, Y. P. Dynamic control of moiré potential in twisted WS2–WSe2 heterostructures. Nano Res. 2022, 15, 7688–7694.
Crossref Google Scholar
[15]

Min, L. J.; Tan, H. X.; Xie, Z. J.; Miao, L. X.; Zhang, R. X.; Lee, S. H.; Gopalan, V.; Liu, C. X.; Alem, N.; Yan, B. H. et al. Strong room-temperature bulk nonlinear Hall effect in a spin-valley locked Dirac material. Nat. Commun. 2023, 14, 364.
Crossref Google Scholar
[16]

Wu, X. P.; Wang, X.; Li, H. L.; Zeng, Z. X. S.; Zheng, B. Y.; Zhang, D. L.; Li, F.; Zhu, X. L.; Jiang, Y.; Pan, A. L. Vapor growth of WSe2/WS2 heterostructures with stacking dependent optical properties. Nano Res. 2019, 12, 3123–3128.
Crossref Google Scholar
[17]

Bae, S.; Matsumoto, K.; Raebiger, H.; Shudo, K. I.; Kim, Y. H.; Handegård, Ø. S.; Nagao, T.; Kitajima, M.; Sakai, Y.; Zhang, X. et al. K-point longitudinal acoustic phonons are responsible for ultrafast intervalley scattering in monolayer MoSe2. Nat. Commun. 2022, 13, 4279.
Crossref Google Scholar
[18]

Zhao, C.; Norden, T.; Zhang, P. Y.; Zhao, P. Q.; Cheng, Y. C.; Sun, F.; Parry, J. P.; Taheri, P.; Wang, J. Q.; Yang, Y. H. et al. Enhanced valley splitting in monolayer WSe2 due to magnetic exchange field. Nat. Nanotechnol. 2017, 12, 757–762.
Crossref Google Scholar
[19]

Nagler, P.; Ballottin, M. V.; Mitioglu, A. A.; Mooshammer, F.; Paradiso, N.; Strunk, C.; Huber, R.; Chernikov, A.; Christianen, P. C. M.; Schüller, C. et al. Giant magnetic splitting inducing near-unity valley polarization in van der Waals heterostructures. Nat. Commun. 2017, 8, 1551.
Crossref Google Scholar
[20]

Zou, C. J.; Cong, C. X.; Shang, J. Z.; Zhao, C.; Eginligil, M.; Wu, L. S.; Chen, Y.; Zhang, H. B.; Feng, S.; Zhang, J. et al. Probing magnetic-proximity-effect enlarged valley splitting in monolayer WSe2 by photoluminescence. Nano Res. 2018, 11, 6252–6259.
Crossref Google Scholar
[21]

Ge, M.; Wang, H.; Wu, J. Z.; Si, C.; Zhang, J. F.; Zhang, S. B. Enhanced valley splitting of WSe2 in twisted van der Waals WSe2/CrI3 heterostructures. npj Comput. Mater. 2022, 8, 32.
Crossref Google Scholar
[22]

Zhang, J.; Du, L. J.; Feng, S.; Zhang, R. W.; Cao, B. C.; Zou, C. J.; Chen, Y.; Liao, M. Z.; Zhang, B. L.; Yang, S. A. et al. Enhancing and controlling valley magnetic response in MoS2/WS2 heterostructures by all-optical route. Nat. Commun. 2019, 10, 4226.
Crossref Google Scholar
[23]

Tang, C. L.; Zhang, Z. W.; Lai, S.; Tan, Q. H.; Gao, W. B. Magnetic proximity effect in graphene/CrBr3 van der Waals heterostructures. Adv. Mater. 2020, 32, 1908498.
Crossref Google Scholar
[24]

Zhang, D.; Seyler, K. L.; Linpeng, X. Y.; Cheng, R.; Sivadas, N.; Huang, B.; Schmidgall, E.; Taniguchi, T.; Watanabe, K.; McGuire, M. A. et al. Van der Waals engineering of ferromagnetic semiconductor heterostructures for spin and valleytronics. Sci. Adv. 2017, 3, e1603113.
Crossref Google Scholar
[25]

Zhong, D.; Seyler, K. L.; Linpeng, X. Y.; Wilson, N. P.; Taniguchi, T.; Watanabe, K.; Mcguire, M. A.; Fu, K. M. C.; Xiao, D.; Yao, W. et al. Layer-resolved magnetic proximity effect in van der Waals heterostructures. Nat. Nanotechnol. 2020, 15, 187–191.
Crossref Google Scholar
[26]

Liu, Y. P.; Gao, Y. J.; Zhang, S. Y.; He, J.; Yu, J.; Liu, Z. W. Valleytronics in transition metal dichalcogenides materials. Nano Res. 2019, 12, 2695–2711.
Crossref Google Scholar
[27]

Dang, J. C.; Yang, M. W.; Xie, X.; Yang, Z.; Dai, D. J.; Zuo, Z. C.; Wang, C.; Jin, K. J.; Xu, X. L. Enhanced valley polarization in WS2/LaMnO3 heterostructure. Small 2022, 18, 2106029.
Crossref Google Scholar
[28]

Peng, B.; Li, Q.; Liang, X.; Song, P.; Li, J.; He, K. L.; Fu, D. Y.; Li, Y.; Shen, C.; Wang, H. L. et al. Valley polarization of trions and magnetoresistance in heterostructures of MoS2 and yttrium iron garnet. ACS Nano 2017, 11, 12257–12265.
Crossref Google Scholar
[29]

Lyons, T. P.; Gillard, D.; Molina-Sánchez, A.; Misra, A.; Withers, F.; Keatley, P. S.; Kozikov, A.; Taniguchi, T.; Watanabe, K.; Novoselov, K. S. et al. Interplay between spin proximity effect and charge-dependent exciton dynamics in MoSe2/CrBr3 van der Waals heterostructures. Nat. Commun. 2020, 11, 6021.
Crossref Google Scholar
[30]

Mendes, J. B. S.; Alves Santos, O.; Meireles, L.   M.; Lacerda, R.   G.; Vilela-Leão, L.   H.; Machado, F.   L.   A.; Rodríguez-Suárez, R.  L.; Azevedo, A.; Rezende, S.  M. Spin-current to charge-current conversion and magnetoresistance in a hybrid structure of graphene and yttrium iron garnet. Phys. Rev. Lett. 2015, 115, 226601.
Crossref Google Scholar
[31]

Wang, Z. Y.; Tang, C.; Sachs, R.; Barlas, Y.; Shi, J. Proximity-induced ferromagnetism in graphene revealed by the anomalous Hall effect. Phys. Rev. Lett. 2015, 114, 016603.
Crossref Google Scholar
[32]

Joshi, J.; Zhou, T.; Krylyuk, S.; Davydov, A. V.; Žutić, I.; Vora, P. Localized excitons in NbSe2–MoSe2 heterostructures. ACS Nano 2020, 14, 8528–8538.
Crossref Google Scholar
[33]

Wang, Q. X.; Maisch, J.; Tang, F. D.; Zhao, D.; Yang, S.; Joos, R.; Portalupi, S. L.; Michler, P.; Smet, J. H. Highly polarized single photons from strain-induced quasi-1D localized excitons in WSe2. Nano Lett. 2021, 21, 7175–7182.
Crossref Google Scholar
[34]

Förste, J.; Tepliakov, N. V.; Kruchinin, S. Y.; Lindlau, J.; Funk, V.; Förg, M.; Watanabe, K.; Taniguchi, T.; Baimuratov, A. S.; Högele, A. Exciton g-factors in monolayer and bilayer WSe2 from experiment and theory. Nat. Commun. 2020, 11, 4539.
Crossref Google Scholar
[35]

He, Q. L.; Hughes, T. L.; Armitage, N. P.; Tokura, Y.; Wang, K. L. Topological spintronics and magnetoelectronics. Nat. Mater. 2022, 21, 15–23.
Crossref Google Scholar
[36]

Hu, J. X.; Luo, J. B.; Zheng, Y. T.; Chen, J. Y.; Omar, G. J.; Wee, A. T. S.; Ariando, A. Magnetic proximity effect at the interface of two-dimensional materials and magnetic oxide insulators. J. Alloys Compd. 2022, 911, 164830.
Crossref Google Scholar
[37]

Macneill, D.; Heikes, C.; Mak, K. F.; Anderson, Z.; Kormányos, A.; Zólyomi, V.; Park, J.; Ralph, D. C. Breaking of valley degeneracy by magnetic field in monolayer MoSe2. Phys. Rev. Lett. 2015, 114, 037401.
Crossref Google Scholar
[38]

Lyons, T. P.; Gillard, D. J.; Leblanc, C.; Puebla, J.; Solnyshkov, D. D.; Klompmaker, L.; Akimov, I. A.; Louca, C.; Muduli, P.; Genco, A. et al. Giant effective Zeeman splitting in a monolayer semiconductor realized by spin-selective strong light-matter coupling. Nat. Photon. 2022, 16, 632–636.
Crossref Google Scholar
[39]

Lazić, P.; Belashchenko, K. D.; Žutić, I. Effective gating and tunable magnetic proximity effects in two-dimensional heterostructures. Phys. Rev. B 2016, 93, 241401(R).
Crossref Google Scholar
[40]

Zhang, Z. W.; Huang, Z. W.; Li, J.; Wang, D.; Lin, Y.; Yang, X. D.; Liu, H.; Liu, S.; Wang, Y. L.; Li, B. et al. Endoepitaxial growth of monolayer mosaic heterostructures. Nat. Nanotechnol. 2022, 17, 493–499.
Crossref Google Scholar
Nano Research
Volume 16 Issue 7,
July 2023
Pages 10580-10586
DOI: 10.1007/s12274-023-5865-x
Cite this article:
Zheng H, Wu B, Wang C-T, et al. Enhanced valley polarization in WSe2/YIG heterostructures via interfacial magnetic exchange effect. Nano Research, 2023, 16(7): 10580-10586. https://doi.org/10.1007/s12274-023-5865-x
Topics:
Semiconductor devices

636

Views

10

Crossref

8

Web of Science

8

Scopus

0

CSCD

Altmetrics
Received: 04 May 2023
Revised: 21 May 2023
Accepted: 23 May 2023
Published: 30 June 2023
© Tsinghua University Press 2023
Return