TY - JOUR
T1 - Enhanced valley splitting in monolayer WSe2 due to magnetic exchange field
AU - Zhao, Chuan
AU - Norden, Tenzin
AU - Zhang, Peiyao
AU - Zhao, Puqin
AU - Cheng, Yingchun
AU - Sun, Fan
AU - Parry, James P.
AU - Taheri, Payam
AU - Wang, Jieqiong
AU - Yang, Yihang
AU - Scrace, Thomas
AU - Kang, Kaifei
AU - Yang, Sen
AU - Miao, Guo Xing
AU - Sabirianov, Renat
AU - Kioseoglou, George
AU - Huang, Wei
AU - Petrou, Athos
AU - Zeng, Hao
PY - 2017/8/1
Y1 - 2017/8/1
N2 - 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 valleys1,2, which offers unique opportunities for valley control through the helicity of light3-5. Lifting the valley degeneracy by Zeeman splitting has been demonstrated recently, which may enable valley control by a magnetic field6-9. However, the realized valley splitting is modest (∼0.2 meV TC1). 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 ∼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.
AB - 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 valleys1,2, which offers unique opportunities for valley control through the helicity of light3-5. Lifting the valley degeneracy by Zeeman splitting has been demonstrated recently, which may enable valley control by a magnetic field6-9. However, the realized valley splitting is modest (∼0.2 meV TC1). 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 ∼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.
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U2 - 10.1038/NNANO.2017.68
DO - 10.1038/NNANO.2017.68
M3 - Article
C2 - 28459469
AN - SCOPUS:85018345870
VL - 12
SP - 757
EP - 762
JO - Nature Nanotechnology
JF - Nature Nanotechnology
SN - 1748-3387
IS - 8
ER -