| Author(s): |
Joseph A. Stroscio; Gregory M. Rutter; D. L. Miller; K. Kubista; W. A. de Heer; Phillip N. First; |
| Title: |
Observing the Quantization of Zero Mass Carriers in Graphene |
| Published: |
May 15, 2009 |
| Abstract: |
Application of a magnetic field to conductors causes the charge carriers to circulate in cyclotron orbits with quantized energies called Landau levels (LLs). These are equally spaced in normal metals and two-dimensional electron gases. In graphene, however, the charge carrier velocity is independent of their energy (like massless photons). Consequently, the LL energies are not equally spaced and include a characteristic zero-energy state (the n = 0 LL). With the use of scanning tunneling spectroscopy of graphene grown on silicon carbide, we directly observed the discrete, non-equally spaced energy-level spectrum of LLs, including the hallmark zero-energy state of graphene. We also detected characteristic magneto-oscillations in the tunneling conductance and mapped the electrostatic potential of graphene by measuring spatial variations in the energy of the n = 0 LL. |
| Citation: |
Science |
| Volume: |
324 |
| Pages: |
pp. 924 - 927 |
| Keywords: |
graphene;SiC;scanning tunneling microscopy;Landau quantization |
| Research Areas: |
Physics, Condensed Matter Physics, Surface Physics |
| PDF version: |
 Click here to retrieve PDF version of paper (4MB) |
