Thu, 21 Aug 2008 09:51:58 BST CiteULike: kas's Girit http://www.citeulike.org/user/kas/author/Girit CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/kas/article/2805107 <i>Science, Vol. 320, No. 5873. (11 April 2008), pp. 206-209.</i><br /><br />Two-dimensional graphene monolayers and bilayers exhibit fascinating electrical transport behaviors. Using infrared spectroscopy, we find that they also have strong interband transitions and that their optical transitions can be substantially modified through electrical gating, much like electrical transport in field-effect transistors. This gate dependence of interband transitions adds a valuable dimension for optically probing graphene band structure. For a graphene monolayer, it yields directly the linear band dispersion of Dirac fermions, whereas in a bilayer, it reveals a dominating van Hove singularity arising from interlayer coupling. The strong and layer-dependent optical transitions of graphene and the tunability by simple electrical gating hold promise for new applications in infrared optics and optoelectronics. 10.1126/science.1152793 Gate-Variable Optical Transitions in Graphene Feng Wang Yuanbo Zhang Chuanshan Tian Caglar Girit Alex Zettl Michael Crommie Ron Shen doi:10.1126/science.1152793 Science, Vol. 320, No. 5873. (11 April 2008), pp. 206-209. 2008-05-16T11:36:28-00:00 2008 Science 320 5873 206 209 bilayer experimental graphene infrared optics