Enhanced Valley Splitting in Monolayer WSe2 by Phase Engineering

被引：22

作者：

Liu, Haiyang ^{[1
]}

Fu, Deyi ^{[1
]}

Li, Xu ^{[1
]}

Han, Junbo ^{[2
,3
]}

Chen, Xiaodie ^{[2
,3
]}

Wu, Xuefeng ^{[1
]}

Sun, Baofan ^{[1
]}

Tang, Weiqing ^{[1
]}

Ke, Congming ^{[1
]}

Wu, Yaping ^{[1
]}

Wu, Zhiming ^{[1
]}

Kang, Junyong ^{[1
]}

机构：

[1] Xiamen Univ, Dept Phys, OSED, Fujian Prov Key Lab Semicond Mat & Applicat, Xiamen 361005, Peoples R China

[2] Huazhong Univ Sci & Technol, Wuhan Natl High Magnet Field Ctr, Wuhan 430074, Peoples R China

[3] Huazhong Univ Sci & Technol, Sch Phys, Wuhan 430074, Peoples R China

来源：

ACS NANO | 2021年 / 15卷 / 05期

基金：

中国国家自然科学基金;

关键词：

valleytronics; H phase; T phase; phase transition; 2D transition metal dichalcogenides; MOS2; TRANSITION; POLARIZATION; NANOSHEETS; WS2;

D O I：

10.1021/acsnano.0c08305

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Lifting the valley degeneracy in two-dimensional transition metal dichalcogenides could promote their applications in information processing. Various external regulations, including magnetic substrate, magnetic doping, electric field, and carrier doping, have been implemented to enhance the valley splitting under the magnetic field. Here, a phase engineering strategy, through modifying the intrinsic lattice structure, is proposed to enhance the valley splitting in monolayer WSe2. The valley splitting in hybrid H and T phase WSe2 is tunable by the concentration of the T phase. An obvious valley splitting of similar to 4.1 meV is obtained with the T phase concentration of 31% under +/- 5 T magnetic fields, which corresponds to an effective Lande g aff factor of -14, about 3.5-fold of that in pure H-WSe2. Comparing the temperature and magnetic field dependent polarized photoluminescence and also combining the theoretical simulations reveal the enhanced valley splitting is dominantly attributed to exchange interaction of H phase WSe2 with the local magnetic moments induced by the T phase. This finding provides a convenient solution for lifting the valley degeneracy of two-dimensional materials.

引用

页码：8244 / 8251

页数：8

共 46 条

[1] Colloquium:: Metallic behavior and related phenomena in two dimensions [J].

Abrahams, E ;

Kravchenko, SV ;

Sarachik, MP .

REVIEWS OF MODERN PHYSICS, 2001, 73 (02) :251-266

[2]

Acerce M, 2015, NAT NANOTECHNOL, V10, P313, DOI [10.1038/nnano.2015.40, 10.1038/NNANO.2015.40]

[3] Magnetic control of valley pseudospin in monolayer WSe2 [J].

Aivazian, G. ;

Gong, Zhirui ;

Jones, Aaron M. ;

Chu, Rui-Lin ;

Yan, J. ;

Mandrus, D. G. ;

Zhang, Chuanwei ;

Cobden, David ;

Yao, Wang ;

Xu, X. .

NATURE PHYSICS, 2015, 11 (02) :148-152

[4] Synthesis of Wafer-Scale Monolayer WS2 Crystals toward the Application in Integrated Electronic Devices [J].

Chen, Jiajun ;

Shao, Kai ;

Yang, Weihuang ;

Tang, Weiqing ;

Zhou, Jiangpeng ;

He, Qinming ;

Wu, Yaping ;

Zhang, Chunmiao ;

Li, Xu ;

Yang, Xu ;

Wu, Zhiming ;

Kang, Junyong .

ACS APPLIED MATERIALS & INTERFACES, 2019, 11 (21) :19381-19387

[5] Quantum Dots of 1T Phase Transitional Metal Dichalcogenides Generated via Electrochemical Li Intercalation [J].

Chen, Wenshu ;

Gu, Jiajun ;

Liu, Qinglei ;

Luo, Ruichun ;

Yao, Lulu ;

Sun, Boya ;

Zhang, Wang ;

Su, Huilan ;

Chen, Bin ;

Liu, Pan ;

Zhang, Di .

ACS NANO, 2018, 12 (01) :308-316

[6] Prediction of two-dimensional diluted magnetic semiconductors: Doped monolayer MoS2 systems [J].

Cheng, Y. C. ;

Zhu, Z. Y. ;

Mi, W. B. ;

Guo, Z. B. ;

Schwingenschloegl, U. .

PHYSICAL REVIEW B, 2013, 87 (10)

[7] Observation of Magnetic Proximity Effect Using Resonant Optical Spectroscopy of an Electrically Tunable MoSe2/CrBr3 Heterostructure [J].

Ciorciaro, Livio ;

Kroner, Martin ;

Watanabe, Kenji ;

Taniguchi, Takashi ;

Imamoglu, Atac .

PHYSICAL REVIEW LETTERS, 2020, 124 (19)

[8] Valley-dependent many-body effects in two-dimensional semiconductors [J].

Das Sarma, S. ;

Hwang, E. H. ;

Li, Qi .

PHYSICAL REVIEW B, 2009, 80 (12)

[9] Pure and stable metallic phase molybdenum disulfide nanosheets for hydrogen evolution reaction [J].

Geng, Xiumei ;

Sun, Weiwei ;

Wu, Wei ;

Chen, Benjamin ;

Al-Hilo, Alaa ;

Benamara, Mourad ;

Zhu, Hongli ;

Watanabe, Fumiya ;

Cui, Jingbiao ;

Chen, Tar-pin .

NATURE COMMUNICATIONS, 2016, 7

[10] Excellent photoresponse performances of graphene/metallic WSe2 nanosheet heterostructure films [J].

He, H-Y ;

He, Z. ;

Shen, Q. .

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING, 2020, 107

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