title: Probing the Spin-Polarized Electronic Band Structure in Monolayer Transition Metal Dichalcogenides by Optical Spectroscopy.
abstract: We study the electronic band structure in the K/K' valleys of the Brillouin zone of monolayer WSe2and MoSe2by optical reflection and photoluminescence spectroscopy on dual-gated field-effect devices. Our experiment reveals the distinct spin polarization in the conduction bands of these compounds by a systematic study of the doping dependence of the A and B excitonic resonances. Electrons in the highest-energy valence band and the lowest-energy conduction band have antiparallel spins in monolayer WSe2and parallel spins in monolayer MoSe2. The spin splitting is determined to be hundreds of meV for the valence bands and tens of meV for the conduction bands, which are in good agreement with first-principles calculations. These values also suggest that both n- and p-type WSe2and MoSe2can be relevant for spin- and valley-based applications.
authors.affiliation: Department of Physics and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802-6300, United States.
authors.forename: Zefang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Physics, Case Western Reserve University , Cleveland, Ohio 44106-7079, United States.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Physics and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802-6300, United States.
authors.forename: Kin Fai
authors.identifier: 0000-0002-5768-199X
authors.initials: KF
authors.lastname: Mak
authors.affiliation: Department of Physics and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802-6300, United States.|Department of Physics, Case Western Reserve University , Cleveland, Ohio 44106-7079, United States.
authors.forename: Jie
authors.initials: J
authors.lastname: Shan
mesh_terms: D018011:Chalcogens / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry*; D004583:Electrons; D008982:Molybdenum / Q000737:chemistry*; D036103:Nanotechnology; D018036:Selenium Compounds / Q000737:chemistry*; D012666:Semiconductors; D013057:Spectrum Analysis / Q000379:methods; D014414:Tungsten / Q000737:chemistry*
chemical_list: D018011:Chalcogens; D004220:Disulfides; D018036:Selenium Compounds; D008982:Molybdenum; D014414:Tungsten
keywords: Spin-dependent electronic structure; optical spectroscopy; transition metal dichalcogenides; two-dimensional materials