Long-Wavelength Local Density of States Oscillations Near Graphene Step Edges

• Main Authors: Xue, Jiamin (Author), Watanabe, K. (Author), Taniguchi, T. (Author), LeRoy, Brian J. (Author), Sanchez-Yamagishi, Javier D. (Contributor), Jarillo-Herrero, Pablo (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society (APS), 2012-03-08T19:53:09Z.
• Subjects: Article
• Online Access: Get fulltext

Using scanning tunneling microscopy and spectroscopy, we have studied the local density of states (LDOS) of graphene over step edges in boron nitride. Long-wavelength oscillations in the LDOS are observed with maxima parallel to the step edge. Their wavelength and amplitude are controlled by the energy of the quasiparticles allowing a direct probe of the graphene dispersion relation. We also observe a faster decay of the LDOS oscillations away from the step edge than in conventional metals. This is due to the chiral nature of the Dirac fermions in graphene.
National Science Foundation (U.S.) (Grant No. EECS/0925152)
National Science Foundation (U.S.) (Grant No. CAREER DMR/0953784)
United States. Dept. of Energy. Division of Materials Sciences and Engineering (Grant No. DE-SC0001819)
United States. Office of Naval Research. Multidisciplinary University Research Initiative (2009 US Office of Naval Research Multi University Research Initiative (MURI) on Graphene Advanced Terahertz Engineering (Gate) at MIT, Harvard, and Boston University)