Slashdot links to some discussion originating out of IBM. Yu-Ming Lin, a researcher from Big Blue, explained in an interview that graphene transistors cannot be switched off in the same way as silicon ones. Slashdot and bit-tech both quote Yu-Ming’s explanation as saying:
… there is an important distinction between the graphene transistors that we demonstrated, and the transistors used in a CPU. Unlike silicon, ‘graphene does not have an energy gap, and therefore, graphene cannot be “switched off,” resulting in a small on/off ratio.
The quote is from an as of yet unpublished interview. It isn’t clear if the lack of an energy gap is a quality of graphene as a material or the current way transistors are constructed from it. Given the direct comparisons to silicon, I infer the former. If it were the latter, then the possibility would remain that a different approach could overcome this critical obstacle.
The article goes on to share some more optimistic thoughts from Yu-Ming on plenty of interesting applications within computer chips for graphene. A further quote from Mike Mayberry, Intel’s director of component research, suggests this all may still be theoretical, that more experimentation may be required before we can so confidently declare the practical limits of the material.
Graphene offers considerable advantage over silicon, a few are mentioned in the bit-tech article. I’ve discussed many of them in past posts here and on the podcast. It is intriguing to imagine graphene’s further use in computing, even replacing many of the materials in use today. Mayberry’s quote reminds us of how wide the gap is between such speculation and even tomorrow’s technology just in terms of what we know about silicon and don’t know about graphene.