The Fermi surface geometrical origin of axis-dependent conduction polarity in layered materials.

Autor: He B; Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA., Wang Y; Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA., Arguilla MQ; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA., Cultrara ND; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA., Scudder MR; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA., Goldberger JE; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA., Windl W; Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA.; Department of Physics, The Ohio State University, Columbus, OH, USA., Heremans JP; Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA. heremans.1@osu.edu.; Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA. heremans.1@osu.edu.; Department of Physics, The Ohio State University, Columbus, OH, USA. heremans.1@osu.edu.
Jazyk: angličtina
Zdroj: Nature materials [Nat Mater] 2019 Jun; Vol. 18 (6), pp. 568-572. Date of Electronic Publication: 2019 Mar 18.
DOI: 10.1038/s41563-019-0309-4
Abstrakt: Electronic materials generally exhibit a single isotropic majority carrier type, electrons or holes. Some superlattice 1,2 and hexagonal 3-5 materials exhibit opposite conduction polarities along in-plane and cross-plane directions due to multiple electron and hole bands. Here, we uncover a material genus with this behaviour that originates from the Fermi surface geometry of a single band. NaSn 2 As 2 , a layered metal, has such a Fermi surface. It displays in-plane electron and cross-plane hole conduction in thermopower and exactly the opposite polarity in the Hall effect. The small Nernst coefficient and magnetoresistance preclude multi-band transport. We label this direction-dependent carrier polarity in single-band systems 'goniopolarity'. We expect to find goniopolarity and the Fermi surface geometry that produces it in many metals and semiconductors whose electronic structure is at the boundary between two and three dimensions. Goniopolarity may enable future explorations of complex transport phenomena that lead to unprecedented device concepts.
Databáze: MEDLINE
Externí odkaz: