Year: 2009
Type: article
Abstract: We report measurements of the thermopower $S$ and Nernst signal ${S}_{yx}$ in graphene in a magnetic field $H$. Both quantities show strong quantum oscillations vs the gate voltage ${V}_{g}$. Our measurements for Landau levels of index $n\ensuremath{\ne}0$ are in quantitative agreement with the edge-current model of Girvin and Jonson (GJ). The inferred off-diagonal thermoelectric conductivity ${\ensuremath{\alpha}}_{xy}$ is consistent in magnitude with GJ's prediction. At the Dirac point $(n=0)$, however, the width of the peak in ${\ensuremath{\alpha}}_{xy}$ is very narrow. We discuss the physical meaning of the peak width and the puzzle raised by ${\ensuremath{\alpha}}_{xy}$ for states at the Dirac point.
Source: Physical Review B
Authors: Joseph G. Checkelsky, N. P. Ong
Institution: Princeton University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2076803624