Graphene-based Spin Caloritronics

• Published in: Nano letters Vol. 11; no. 3; pp. 1369 - 1373
• Main Authors: Zeng, Minggang, Feng, Yuanping, Liang, Gengchiau
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 09.03.2011
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electron states; Exact sciences and technology; Fullerenes and related materials; Fullerenes and related materials; diamonds, graphite; Materials science; Methods of electronic structure calculations; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics; Specific materials; Visible and ultraviolet spectra; thermal magnetoresistance effect; spintronics; spin caloritronics; Graphene; spin Seebeck effect; thermal spin components; Ground states; Calcium nitride; Gallium tellurides; Density functional method; Nanotape; Seebeck effect; Absorption spectra; Thermal magnetoresistance; Gates
• ISSN: 1530-6984; 1530-6992; 1530-6992
• DOI: 10.1021/nl2000049

Thermally induced spin transport in magnetized zigzag graphene nanoribbons (M-ZGNRs) is explored using first-principles calculations. By applying temperature difference between the source and the drain of a M-ZGNR device, spin-up and spin-down currents flowing in opposite directions can be induced. This spin Seebeck effect in M-ZGNRs can be attributed to the asymmetric electron−hole transmission spectra of spin-up and spin-down electrons. Furthermore, these spin currents can be modulated and completely polarized by tuning the back gate voltage. Finally, thermal magnetoresistance of ZGNRs between ground states and magnetized states can reach 104% without an external bias. Our results indicate the possibility of developing graphene-based spin caloritronic devices.