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"Two-dimensional gas of massless Dirac fermions in graphene," by K.S. Novoselov and 7 others, Nature,
438(7065): 197-200, 10 November 2005.

[Authors' affiliations: University of Manchester, U.K.; Institute for Microelectronics, Chernogolovka, Russia; Radboud
University of Nijmegen, Netherlands]

Abstract: "Quantum electrodynamics (resulting from the merger of quantum mechanics and relativity theory) has provided a clear understanding of phenomena ranging from particle physics to cosmology and from astrophysics to quantum chemistry. The ideas underlying quantum electrodynamics also influence the theory of condensed matter, but quantum relativistic effects are usually minute in the known experimental systems that can be described accurately by the non-relativistic Schrodinger equation. Here we report an experimental study of a condensed-matter system (graphene, a single atomic layer of carbon) in which electron transport is essentially governed by Dirac's (relativistic) equation. The charge carriers in graphene mimic relativistic particles with zero rest mass and have an effective 'speed of light' c* approximate to 10(6) m s(-1). Our study reveals a variety of unusual phenomena that are characteristic of two-dimensional Dirac fermions. In particular we have observed the following: first, graphene's conductivity never falls below a minimum value corresponding to the quantum unit  of conductance, even when concentrations of charge carriers tend to zero; second, the integer quantum Hall effect in graphene is anomalous in that it occurs at half-integer filling factors; and third, the cyclotron mass m(c) of massless carriers in graphene is described by E = m(c)c(*)(2). This two-dimensional system is not only interesting in itself but also allows access to the subtle and rich physics of quantum electrodynamics in a bench-top experiment."

This 2005 report from Nature was cited 102 times in current journal articles indexed by Thomson Scientific during September-October 2007. Only one other physics paper published in the last two years, aside from reviews, collected a higher number of citations during that two-month period. Prior to the most recent bimonthly count, citations to the paper have accrued as follows:

July-August 2007: 50 citations
May-June 2007: 60
March-April 2007: 27
January-February 2007: 31
November-December 2006: 33
September-October 2006: 21
July-August 2006: 28
May-June 2006: 12
March-April 2006: 7
January-February 2006: 1
November-December 2005: 1

Total citations to date: 373

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