Biaxial Strain and Electric Field Dependent Conductivity of Monolayer WTe2 on Top of Fe3O4(111). Issue 18 (11th August 2016)

• Record Type: Journal Article
• Authors: Song, Yan; Mi, Wenbo; Wang, Xiaocha
• Is Part Of: Advanced materials interfaces. Volume 3:Issue 18(2016)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2016-08-11
• Subjects: biaxial strain -- electric field -- Fe3O4(111) -- interface state -- monolayer WTe2; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.201600581
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract : The biaxial strain and electric field dependent electronic properties of monolayer WTe2 on top of Fe3 O4 (111) are investigated by first‐principles calculations. Our results demonstrate that mechanical strain effectively separates the contributions of interface state and valley states to the conductivity of monolayer WTe2 . Tensile strain shifts the interface state below Fermi level. The conductivity of WTe2 is dominated by valley states. With compressive strain, the interface state is shifted away from the valley state edge. The conductivity is only subject to the spin‐polarized interface state. Applying perpendicular electric field also yields valley‐state‐dominating conductivity. The valley splitting energy reduces from 139 to −68 meV with an electric field of 0.02 V nm −1 . Different from applying strain, valley polarization is robust against wide range of electric field intensity, showing potential applications in spintronic and valleytronic devices. Abstract : The interface state of monolayer WTe2 /Fe3 O4 (111) is sensitive to external physical fields. Applying mechanical strain or electric field can realize valley‐state dominating, spin‐polarized interface‐state dominating, or valley‐polarized conductivity of monolayer WTe2 .