Proposal for a Workshop at the Aspen Center for Physics Summer 2007 Organizers: Prof. Antonio H. Castro Neto (contact person) Department of Physics Boston University 590 Commonwealth Ave. Boston, MA, 02215 Phone: 617-353-6116 Email: [email protected] Prof. Alessandra Lanzara (responsible for working to ensure diversity) Department of Physics University of California Berkeley 321 Birge Hall Berkeley, CA 94720-7300 USA Phones: (510) 642-4863 (campus) (510) 486-5303 (LBL) Email: [email protected] Prof. Francisco (Paco) Guinea Instituto de Ciencia de Materiales de Madrid, CSIC Cantoblanco. E-28049 Madrid, Spain Phone: 34-1-3349047 Email: [email protected] Title: The Physics of Graphene and Graphite Rationale: The discovery of an anomalous integer quantum Hall effect in graphene (a form of two-dimensional carbon) by two independent groups (K.S. Novoselov et al., Nature 438, 197 (2005), and Yuanbo Zhang et al., Nature 438, 201 (2005)) has stirred a lot of interest in the scientific community (see, for instance, Nature “News and Views“ by C. Kane, Nature 438, 168 (2005), and http://physicsweb.org/articles/news/9/11/6/1) as well as in the international media (see, for instance, a BBC News Report on the subject: http://news.bbc.co.uk/1/hi/sci/tech/3944651.stm). The excitement behind this discovery has two main driven forces: basic science, and technological implications. Graphene is a condensed matter realization of the Dirac equation since the electronic dispersion close to the Brillouin zone edges are conical with a Fermi-Dirac velocity of order of one hundredth of the velocity of light. Hence, unlike most of other solids, graphene electrons cannot be described in terms of an effective mass. This fact has strong implications in many of the physical properties of these systems: the electronic density of states vanishes at the Fermi level, there is very poor screening of the Coulomb interaction, the Dirac fermions interact very strongly with disorder such as vacancies, and Landau’s Fermi liquid theory is not applicable. That is, graphene is a non-Fermi liquid system. In fact, graphene share many properties with quasi-two-dimensional d-wave superconductors (such as superconducting cuprates) who can also be described in terms of Dirac-like excitations. As a result of this exotic behavior, graphene has unusual collective excitations (such as zero modes), and an anomalous integer quantum Hall effect with a finite Berry’s phase. There has been an intense experimental effort in recent months in graphene research. Cutting-edge research techniques such as infrared absorption, angle resolved photo-emission (ARPES), and neutron scattering, are being used to study this system. Some of these techniques that have been used so successfully in high temperature superconductivity research, can be directly applied to these materials that also show layered structure. Because of its high electronic mobility, structural flexibility, and capability of being tuned from p-type to n-type doping by the application of a gate voltage (see, K. S. Novoselov et al., Science 306, 666 (2004)), graphene is being considered a breakthrough in terms of carbon-based nano-electronics. In fact, unlike carbon-nanotubes, graphene can be easily patterned with standard lithographic techniques and does not present problems with electric contacts. With the predicted saturation in silicon-based technology due to limitations in miniaturization, integration, yield enhancement, and inter- connectivity (see, for instance, the International Technology Roadmap for Semiconductors, http://www.itrs.net/Common/2004Update/2004Update.htm), there is a growing interest by technology development companies in graphene research. The interest in the anomalous properties of graphene only adds to the intriguing discovery that graphite (a crystal made out a stack of graphene layers) can be made ferromagnetic when sufficiently disordered (see, for instance, the focus page of American Physical Society in 2003, http://focus.aps.org/story/v12/st20). This discovery still remains unexplained theoretically (even in fact of many proposals) and has drawn a lot of attention to modern carbon research (see http://physicsweb.org/article/news/5/12/11\#11, and http://nanotechweb.org/articles/news/3/3/13 ). It is quite clear to us that graphene research will “explode” in the next few months (as one can see by the number of papers posted in the cond-mat archive recently). Because of its tradition, infrastructure, and location, the Aspen Center for Physics is in a special position to host the first international workshop in graphene research in the summer of 2007. We have assembled a list of key and proposed participants that represents respected scientists who are currently doing significant in the field. We expect that this list will change with time until the date of the workshop. Proposed dates: 3 July – 30 July (preferred); 10 July – 6 August (acceptable); 19 June – 9 July (acceptable). Key participants (in alphabetical order): 1) Tsuneya Ando (ITI, Japan) – tentative. 2) Dimitri Basov (UCSD, USA) – committed to participate. 3) Walt de Heer (Georgia Tech., USA) – committed to participate. 4) Mildred Dresselhaus (MIT, USA) – committed to participate. 5) Pablo Esquinazi (Leipzig, Germany) – committed to participate. 6) Vladimir Falko (Lancaster, UK) – committed to participate. 7) Andre Geim (Manchester, UK) – committed to participate. 8) Dmitri Khveshchenko (Chapel Hill, USA) – committed to participate. 9) Philip Kim (Columbia Univ., USA) – committed to participate. 10) Peter Littlewood (Cambridge Univ., UK) – tentative. 11) Sergei Sharapov (McMaster Univ., CA) – tentative. 12) Horst Stormer (Columbia Univ., USA) – tentative. Proposed Participants (in alphabetical order): 1) Claire Berger (Laboratoire d'Études des Propriétés Électroniques des Solides, France); 2) Luiz Brey (ICCM, Spain); 3) Matteo D'Astuto (CNRS, France); 4) Eduardo Fradkin (University of Illinois at Urbana-Champaing, USA); 5) H. Fukuyama (University of Tokyo, Japan); 6) Bennett Goldberg (Boston Univesity, USA); 7) G.-H. Gweon (University of California at Berkeley, USA); 8) Duncan Haldane (Princeton University, USA); 9) Ayako Hashimoto (Tsukuba University, Japan); 10) A. Hebard (University of Florida, USA); 11) C. Kane (University of Penn., USA); 12) Yoji Koike (Tohoku University, Japan); 13) Yakov Kopelevich (Unicamp, Brazil); 14) Patrick A. Lee (MIT, USA); 15) Dung-Hai Lee (University of California at Berkeley, USA); 16) S. Louie (University of California at Berkeley, USA); 17) Maria Pilar Lopez-Sancho (ICCM, Spain); 18) Genevieve Loupiasse (Paris); 19) D. Maslov (University of Florida, USA); 20) T. Matsui (University of Tokyo, Japan); 21) E. J. Mele (University of Penn., USA); 22) Y. Niimi (University of Tokyo, Japan); 23) K. Novoselov (University of Manchester, UK); 24) Vitor Pereira (University of Porto, Portugal); 25) Nuno Peres (University of Minho, Portugal); 26) Joao Lopes dos Santos (University of Porto, Portugal); 27) Ben Simons (Cambridge Univ., UK); 28) Siddharth Saxena (Cavendish Laboratory, UK); 29) Manfred Sigrist (ETH, Zurich); 30) Kazu Suenaga (Tsukuba University, Japan); 31) Masatsugu Suzuki (New York State University at Binghamton, USA); 32) Anna Swan (Boston University, USA); 33) Shan-Wen Tsai (University of California at Riverside, USA); 34) Maria Vozmediano (ICCM, Spain); 35) Katsunori Wakabayashi (Hiroshima University, Japan); 36) Tom Weller (University College of London, UK); 37) Y. Zhang (Columbia University, USA); 38) S. Zhou (University of California at Berkeley, USA)..