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Stable and remarkable valley polarization effect is the key to utilizing valley degree of freedom in valleytronic devices. Recently, a novel collinear magnetic material known as altermagnet, distinct from ferromagnets and antiferromagnets, has attracted widespread attention. Theoretical studies have revealed that the monolayer altermagnet V2Se2O exhibits spin-valley locking induced by crystal symmetry rather than conventional time-reversal symmetry. Uniaxial strain can break the corresponding crystal symmetry, leading to a remarkable non-relativistic valley polarization effect. Therefore, beyond uniaxial strain, are there alternative strategies to break the crystal symmetry in altermagnets and achieve remarkable valley polarization? Based on firstprinciples calculations and symmetry analysis, we reveal that valley polarization effect in monolayer V2Se2O altermagnet is correlated with the net magnetic moment between magnetic atoms V under uniaxial strain, proposing two strategies for achieving giant valley polarization effect. Firstly, substituting one V atom in V2Se2O with Cr to construct a ferrimagnetic monolayer VCrSe2O enhances the net magnetic moment between magnetic atoms, thereby realizing giant valley polarization effect. Applying uniaxial strain along either the a-axis or b-axis significantly increases the value of valley polarization which exhibits a nearly linear relationship with the net magnetic moments between the magnetic atoms. Secondly, constructing a van der Waals heterostructure composed of V2Se2O and α-SnO monolayers breaks mirror symmetry, as a result, inducing a net magnetic moment, which in turn induces remarkable valley polarization effect. Compressing the interlayer distance of the heterostructure enables an increment of the net magnetic moment between V atoms, enhancing the value of valley polarization to nearly 400 meV. This work reveals that valley polarization in monolayer altermagnets is correlated with the net magnetic moment between magnetic atoms. Then, we propose two strategies to achieve giant valley polarization based on monolayer altermagnets, providing theoretical guidance for the potential applications of ferrimagnetic monolayers and heterostructures constructed from altermagnets in valleytronics.
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Keywords:
- Valley degree of freedom /
- Monolayer altermagnets /
- Valley polarization /
- Ferrimagnetic /
- Van der Waals heterostructure
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[1] Li L, Shao L, Liu X, Gao A, Wang H, Zheng B, Hou G, Shehzad K, Yu L, Miao F, Shi Y, Xu Y, Wang X 2020 Nat. Nanotechnol. 15 743
[2] Sun Z H, Guan H M, Fu L, Shen B, Tang N 2021 Acta Phys. Sin. 70 027302 (in Chinese) [孙真昊，管鸿明，付雷，沈波，唐宁 2021 物理学报 70 027302]
[3] Schaibley J R, Yu H, Clark G, Rivera P, Ross J S, Seyler K L, Yao W, Xu X 2016 Nat. Rev. Mater. 1 16055
[4] Xiao D, Liu G B, Feng W, Xu X, Yao W 2012 Phys. Rev. Lett. 108 196802
[5] Xu X, Yao W, Xiao D, Heinz T F 2014 Nat. Phys. 10 343
[6] MacNeill D, Heikes C, Mak K F, Anderson Z, Kormányos A, Zólyomi V, Park J, Ralph D C 2015 Phys. Rev. Lett. 114 037401
[7] Li Y, Ludwig J, Low T, Chernikov A, Cui X, Arefe G, Kim Y D, Van Der Zande A M, Rigosi A, Hill H M, Kim S H, Hone J, Li Z, Smirnov D, Heinz T F 2014 Phys. Rev. Lett. 113 266804
[8] Aivazian G, Gong Z, Jones A M, Chu R L, Yan J, Mandrus D G, Zhang C, Cobden D, Yao W, Xu X 2015 Nat. Phys. 11 148
[9] Srivastava A, Sidler M, Allain A V, Lembke D S, Kis A, Imamoğlu A 2015 Nat. Phys. 11 141
[10] Peng R, Ma Y, Zhang S, Huang B, Dai Y 2018 J Phys. Chem. Lett. 9 3612
[11] Zhou J, Lin J, Sims H, Jiang C, Cong C, Brehm J A, Zhang Z, Niu L, Chen Y, Zhou Y, Wang Y, Liu F, Zhu C, Yu T, Suenaga K, Mishra R, Pantelides S T, Zhu Z, Gao W, Liu Z, Zhou W 2020 Adv. Mater. 32 1906536
[12] Matsuoka H, Habe T, Iwasa Y, Koshino M, Nakano M 2022 Nat. Commun. 13 5129
[13] Zhong D, Seyler K L, Linpeng X, Wilson N P, Taniguchi T, Watanabe K, McGuire M A, Fu K M C, Xiao D, Yao W, Xu X 2020 Nat. Nanotechnol. 15 187
[14] Abdollahi M, Tagani M B 2023 Phys. Rev. B 108 024427
[15] Zhang W, Zhu H, Zhang W, Wang J, Zhang T, Yang S, Shao B, Zuo X 2024 Appl. Surf. Sci. 647 158986
[16] Mak K F, McGill K L, Park J, McEuen P L 2014 Science 344 1489
[17] Mak K. F, He K, Shan J, Heinz T F 2012 Nat. Nanotechnol. 7 494
[18] Hsu W T, Chen Y L, Chen C H, Liu P S, Hou T H, Li L J, Chang W H 2015 Nat. Commun. 6 8963
[19] Tong W Y, Gong S J, Wan X, Duan C G 2016 Nat. Commun. 7 13612
[20] Xie W, Zhang L, Yue Y, Li M, Wang H 2024 Phys. Rev. B 109 024406
[21] Pan W 2022 Phys. Rev. B 106 125122
[22] Zhao J, Zhang T, Peng R, Dai Y, Huang B, Ma Y 2022 J Phys. Chem. Lett. 13 8749
[23] Feng X, Xu X, He Z, Peng R, Dai Y, Huang B, Ma Y 2021 Phys. Rev. B 104 075421
[24] Xie W, Xu X, Li M, Wang H 2023 J Magn. Magn. Mater. 573 170662
[25] Zhao P, Ma Y, Lei C, Wang H, Huang B, Dai Y 2019 Appl. Phys. Lett. 115 261605
[26] Sheng K, Zhang B, Yuan H K, Wang Z Y 2022 Phys. Rev. B 105 195312
[27] Cheng H X, Zhou J, Ji W, Zhang Y N, Feng Y P 2021 Phys. Rev. B 103 125121
[28] Liu Y, Feng Y, Zhang T, He Z, Dai Y, Huang B, Ma Y 2023 Adv. Funct. Mater. 33 2305130
[29] Zhang D, Li A, Chen X, Zhou W, Ouyang F 2022 Phys. Rev. B 105 085408
[30] Li P, Liu B, Chen S, Zhang W X, Guo Z X 2024 Chin. Phys. B 33 017505
[31] Luo C, Huang Z, Qiao H, Qi X, Peng X 2024 J Phys. Mater. 7 022006
[32] Šmejkal L, Sinova J, Jungwirth T 2022 Phys. Rev. X 12 031042
[33] Šmejkal L, Sinova J, Jungwirth T 2022 Phys. Rev. X 12 040501
[34] Šmejkal L, González-Hernández R, Jungwirth T, Sinova J 2020 Sci. Adv. 6 eaaz8809
[35] Leeb V, Mook A, Šmejkal L, Knolle J 2024 Phys. Rev. Lett. 132 236701
[36] Reimers S, Odenbreit L, Šmejkal L, Strocov V N, Constantinou P, Hellenes A B, Jaeschke Ubiergo R, Campos W H, Bharadwaj V K, Chakraborty A, Denneulin T, Shi W, Dunin-Borkowski R E, Das S, Kläui M, Sinova J, Jourdan M 2024 Nat. Commun. 15 2116
[37] Ma H Y, Hu M, Li N, Liu J, Yao W, Jia J F, Liu J 2021 Nat. Commun. 12 2846
[38] Yang G, Li Z, Yang S, Li J, Zheng H, Zhu W, Pan Z, Xu Y, Cao S, Zhao W, Jana A, Zhang J, Ye M, Song Y, Hu L H, Yang L, Fujii J, Vobornik I, Shi M, Yuan H, Zhang Y, Xu Y, Liu Y 2025 Nat. Commun. 16 1442
[39] Zhu Y, Chen T, Li Y, Qiao L, Ma X, Liu C, Hu T, Gao H, Ren W 2024 Nano Lett. 24 472
[40] Wu Y, Deng L, Yin X, Tong J, Tian F, Zhang X 2024 Nano Lett. 24 10534
[41] Chen X, Wang D, Li L, Sanyal B 2023 Appl. Phys. Lett. 123 022402
[42] Guo S D, Guo X S, Cheng K, Wang K, Ang Y S 2023 Appl. Phys. Lett. 123 082401
[43] Li J Y, Fan A D, Wang, Y K, Zhang Y, Li S 2024 Appl. Phys. Lett. 125 222404
[44] Jiang Y, Zhang X, Bai H, Tian Y, Zhang B, Gong W J, Kong X 2025 Appl. Phys. Lett. 126 053102
[45] Tan C Y, Gao Z F, Yang H C, Liu Z X, Liu K, Guo P J, Lu Z Y 2025 Phys. Rev. B 111 094411
[46] Zhang R W, Cui C, Li R, Duan J, Li L, Yu Z M, Yao Y 2024 Phys. Rev. Lett. 133 056401
[47] Xie W, Xu X, Yue Y, Xia H, Wang H 2025 Phys. Rev. B 111 134429
[48] Kresse G, Furthmüller J 1996 Comput. Mater. Sci. 6 15
[49] Blöchl P E 1994 Phys. Rev. B 50 17953
[50] Perdew J P, Burke K, Ernzerhof M 1996 Phys. Rev. Lett. 77 3865
[51] Dudarev S L, Botton G A, Savrasov S Y, Humphreys C J, Sutton A P 1998 Phys. Rev. B 57 1505
[52] Grimme S, Antony J, Ehrlich S, Krieg H 2010 J Chem. Phys. 132 154104
[53] Huang C, Feng J, Wu F, Ahmed D, Huang B, Xiang H, Deng K, Kan E 2018 J. Am. Chem. Soc. 140 11519
[54] Li X Y, Li Z H, Cao S G, Han J N, Fan Z Q, Zhang Z H 2024 Sci. Sin. Phys. Mech. Astron. 54 126811 (in Chinese) [李鑫焱，李占海，曹胜果，韩佳凝，范志强，张振华 2024 中国科学: 物理学 力学 天文学 54 126811]
[55] Seixas L, Rodin A S, Carvalho A, Castro Neto A H 2016 Phys. Rev. Lett. 116 206803
[56] Liu S Q, Li S Z, Si J S, Zhang W B 2023 Sci. Sin. Phys. Mech. Astron. 53 117311 (in Chinese) [刘水青，李树宗，司君山，张卫兵 2023 中国科学: 物理学 力学 天文学 53 117311]
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