The fight for the best quantum bit (qubit)

June 25, 2008

Our results give us, for the first time, the possibility to understand the interaction between just two electrons placed next to each other in a carbon nanotube. A groundbreaking discovery, which is fundamental for the creation of a quantum mechanical bit, a so-called quantum bit - the cornerstone of a quantum computer, explains Henrik Jørgensen, who is one of the many researchers competing on an international level to be the first to make a quantum bit in a carbon nanotube.

The ability to produce a quantum computer is still some years ahead in the future, the implementation will, however, mean a revolution within the computer industry. This is due to the quantum mechanical computation method, which quickly will be able to solve certain complicated calculations that on an ordinary computer would take more than the lifetime of the Universe to calculate.

Who will be the first?

Over the past years there has been a tremendously increasing interest in developing a quantum computer within the international world of researchers. The production of a quantum computer is enormously challenging and demands development of new theories and new technologies by research-groups all over the world. Henrik Jørgensen's results have been developed in close collaboration with the Hitachi Cambridge Laboratory in England.

Adviser and Vice-Chairman at the Nano-Science Center, Professor Poul Erik Lindelof, says - We have been studying the quantum mechanical properties of carbon nanotubes for ten years, and today we are one of the leading laboratories within this field of research. I believe Henrik Jørgensen's experimental work can prove to be just the right way forward.

Kasper Grove Rasmussen is joint author of the article. He says - We use carbon nanotubes due to their unique electronic and material properties and not least due to the absence of disturbing magnetism from the atom nuclei which is found in certain competing materials.

At present it is not possible to say which material will be the most suitable for the quantum computer, or who will be the first to realize a quantum bit in a carbon nanotube, but the researchers at the Nano-Science Center are a big step closer to the solution.

University of Copenhagen

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