2016/10/16 by Chuan Zhao, Tenzin Norden, Puqin Zhao +18 · 3 citations
Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Chemical physics #Condensed matter physics #Field (mathematics) #MXene and MAX Phase Materials #Magnetic field #Materials science #Monolayer #Nanotechnology #Perovskite Materials and Applications #Physics #Quantum mechanics #cond-mat.mes-hall
paper · pdf · doi:10.1038/nnano.2017.68
published as Nature Nanotechnology, 12, 757-762 (2017)
arxiv created 2016/10/16 · openalex created_date 2016/10/28 · openalex publication_date 2017/05/01 · arxiv updated 2018/06/20 · openalex updated_date 2026/08/05
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 broken inversion symmetry possesses two degenerate yet inequivalent valleys, offering unique opportunities for valley control through helicity of light. Lifting the valley degeneracy by Zeeman splitting has been demonstrated recently, which may enable valley control by a magnetic field. However, the realized valley splitting is modest, (~ 0.2 meV/T). 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 magneto-reflectance measurements. Moreover, the splitting follows the magnetization of EuS, a hallmark of the MEF. Utilizing MEF of a magnetic insulator can induce magnetic order, and valley and spin polarization in TMDCs, which may enable valleytronic and quantum computing applications.