By Eugenie Samuel Reich

A high-profile graphene researcher has written to the Nobel prize committee for physics, objecting to errors in its explanation of this year's prize. The award was given to Andre Geim and Konstantin Novoselov of Manchester University, UK, for their work on graphene, a two-dimensional carbon structure that has huge potential in the field of electronics.

Due to the Nobels' prominence, it is not unheard of for disgruntled researchers to criticize a prize committee's decision. But this complaint focuses instead on the quality of the scientific background document issued by the committee to explain why it awarded the prize. "The Nobel Prize committee did not do its homework," says Walt de Heer of Georgia Institute of Technology in Atlanta. He sent his letter to the committee on 17 November.

After enquiries made by Nature in advance of De Heer's letter, the committee is making at least one correction to its online information, says chairman Ingemar Lundström. "Some of the things we also think are mistakes."

De Heer holds patents on the use of graphene in electronics, and made some of the earliest measurements of electronic effects in the material. Geim accuses de Heer of trying to boost his own reputation. "If he complains about Stockholm, some people might start thinking that he contributed something important," says Geim.

De Heer does disagree with the award of the physics prize to Geim and Novoselov, calling it "extremely fast," but he insists that his objections to the prize committee's document are not motivated by sour grapes. "The motive is simply to have the record straight on a document this important," he says. "Its standards have to be higher than for any other prize and they're not."

According to the background document as downloaded by Nature on 17 November, Geim and Novoselov won the 2010 prize for "decisive contributions" to the development of graphene. It explains that the field was ignited by a 2004 paper that the group published in Science.

Series of errors

But de Heer sees a series of errors that he believes overplay the significance of Geim and Novoselov's work at the expense of other researchers. One example is Figure 3 of the document, which is taken from Geim and Novoselov's 2004 paper. The caption says the data were obtained using graphene, which the document defines as "a single atomic layer of carbon". But the result was actually obtained in few-layer graphene (FLG), a multilayer form of carbon also known as graphite. Graphene and graphite have different electronic properties--part of the reason for the tremendous interest in studying single atomic layers.

Geim says the error is not a big deal because he and his colleagues later reported similar data on single-layer graphene in 2005. But De Heer says in his letter to the committee that his own 2004 paper included measurements on a single layer of graphene, even though he did not realize it at the time.

Other mistakes downplay the work of Philip Kim of Columbia University in New York, whom many researchers think should have shared the prize. When the Manchester group published crucial electronic measurements on graphene in Nature in 2005, the paper appeared back-to-back with one from Kim's group. "He made an important contribution and I would gladly have shared the prize with him," says Geim.

Kim says he is honored by the suggestion. "Personally I wish it but it's not working that way," he says. "I respect the decision."

Figure 4 of the Nobel document shows two panels of data, but its caption refers twice to the left panel, which shows data obtained by Novoselov and Geim, and not at all to the right panel, which shows Kim's data. In addition, a citation to Kim's 2005 paper could be read as referring to an inset of data in the figure, leaving the main panel uncited. Kim downplays the errors, calling them editorial in nature.

Complete surprise

De Heer also complains that the main text of the background document exaggerates the importance of Novoselov and Geim's 2004 paper. It states that the study came as a complete surprise to the physics community and that, before their work, graphene had never been isolated and was not thought to be stable. "It is a complete straw man", says De Heer.

That claim by the Nobel committee has irked other graphene researchers as well. "That statement is not accurate," says Paul McEuen at Cornell University in Ithaca, New York. McEuen says that graphene had been made before the 2004 paper, and that several groups were working towards making electrical measurements on it. McEuen says that in his view, the most important contributions were those published in 2005 by Geim and Novoselov and separately by Kim.

Novoselov and Geim argue that the accuracy of the committee's statement is a matter of opinion. Only "a tiny minority" of researchers thought that graphene would be stable, says Geim. He points out that thousands have since voted with their feet by switching fields to work on graphene. Novoselov and Geim's 2004Science paper has received 3,357 citations according to the Web of Knowledge citation index.

Lundström says that the committee is now correcting several points in its document raised by Nature and by De Heer's letter, but says it is unlikely to change its general statement on the significance of the Manchester group's 2004 work. He adds that as a "popular" document, the backgrounder does not necessarily reflect all the information that the committee relied on when awarding the prize.

De Heer also speculates that information from nomination material has been used in the backgrounder. "The document reads like a nomination letter," he says. Per Delsing at Chalmers University of Technology in Göteborg, an adjunct member of the Nobel committee, responds that the committee did extensive research into the field before awarding the prize, but wouldn't comment on the suggestion that material submitted by a nominator might have been used in the preparation of the document. "I cannot reveal that. Many of these things are secret," he says.

The committee has apparently already made one correction to the document. In a version downloaded in October 2010 by Rodney Ruoff at the University of Texas at Austin, the names of Ruoff and five other authors were omitted from a reference to a 2009 paper describing the scaling-up of sheets of graphene. These names are now included. Ruoff says he'd like the Nobel Prize committee to investigate how its document was generated and whether material from nomination letters was incorporated. "This whole experience has left me wondering how the Nobel-prize process works," he says.

However, Klaus von Klitzing of the Max Planck Institute for Solid State Research in Stuttgart, Germany, winner of the 1985 Nobel prize for physics, says he sees no need to criticize this year's committee. He points out that a symposium on graphene was held earlier this year in Stockholm, during which committee members heard from leading graphene researchers including de Heer and Kim. "I believe that members of the Nobel Prize Committee had a good overview about the scientific situation," he says.