Enhanced valley splitting in monolayer WSe2 due to magnetic exchange field

被引：10

作者：

Zhao, Chuan ^{[1
]}

Norden, Tenzin ^{[1
]}

Zhang, Peiyao ^{[1
]}

Zhao, Puqin ^{[1
,2
,3
]}

Cheng, Yingchun ^{[2
,3
]}

Sun, Fan ^{[1
]}

Parry, James P. ^{[1
]}

Taheri, Payam ^{[1
]}

Wang, Jieqiong ^{[4
]}

Yang, Yihang ^{[5
]}

Scrace, Thomas ^{[1
]}

Kang, Kaifei ^{[1
,4
]}

Yang, Sen ^{[4
]}

Miao, Guo-xing ^{[5
]}

Sabirianov, Renat ^{[6
]}

Kioseoglou, George ^{[7
]}

Huang, Wei ^{[2
,3
]}

Petrou, Athos ^{[1
]}

Zeng, Hao ^{[1
,4
]}

机构：

[1] SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA

[2] Nanjing Tech Univ, Jiangsu Natl Synerget Innovat Ctr Adv Mat, Key Lab Flexible Elect, Nanjing 211816, Peoples R China

[3] Nanjing Tech Univ, Jiangsu Natl Synerget Innovat Ctr Adv Mat, Inst Adv Mat, Nanjing 211816, Peoples R China

[4] Xi An Jiao Tong Univ, Sch Sci, MOE Key Lab Nonequilibrium Synth & Modulat Conden, Xian 710049, Peoples R China

[5] Univ Waterloo, Inst Quantum Comp, Waterloo, ON, Canada

[6] Univ Nebraska Omaha, Dept Phys, Omaha, NE 68182 USA

[7] Univ Crete, Dept Mat Sci & Technol, GR-71003 Iraklion, Greece

来源：

NATURE NANOTECHNOLOGY | 2017年 / 12卷 / 08期

基金：

加拿大自然科学与工程研究理事会; 中国国家自然科学基金; 美国国家科学基金会;

关键词：

MOS2; POLARIZATION; GENERATION; WS2;

D O I：

10.1038/NNANO.2017.68

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Exploiting the valley degree of freedom to store and manipulate information provides a novel paradigm for future electronics. A monolayer transition-metal dichalcogenide (TMDC) with a broken inversion symmetry possesses two degenerate yet inequivalent valleys(1,2), which offers unique opportunities for valley control through the helicity of light(3-5). Lifting the valley degeneracy by Zeeman splitting has been demonstrated recently, which may enable valley control by a magnetic field(6-9). However, the realized valley splitting is modest (similar to 0.2 meV T-1). Here we show greatly enhanced valley spitting in monolayer WSe2, utilizing the interfacial magnetic exchange field (MEF) from a ferromagnetic EuS substrate. A valley splitting of 2.5 meV is demonstrated at 1 T by magnetoreflectance measurements and corresponds to an effective exchange field of similar to 12 T. Moreover, the splitting follows the magnetization of EuS, a hallmark of the MEF. Utilizing the MEF of a magnetic insulator can induce magnetic order and valley and spin polarization in TMDCs, which may enable valleytronic and quantum-computing applications(10-12).

引用

页码：757 / +

页数：7

共 35 条

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