First quantum byte created

Thursday, December 1, 2005

Eight calcium ions in a quadrupole ion trap

The Institute of Quantum Optics and Quantum Information at the University of Innsbruck in Austria has created an entanglement of eight quantum particles, yielding a quantum byte or "qubyte", or eight qubits. This is an important step toward the realization of a practical quantum computer, which would use superposed quantum states to perform complex calculations. A detailed writeup of this work is available in English and German. The formal paper was published in the December 1 issue of Nature.

Contributors to the breakthrough are researchers from IQOQI under the supervision of Rainer Blatt and Hartmut Häffner in coaction with Otfried Gühne and Wolfgang Dür of the Innsbruck research group directed by Hans Jürgen Briegelhave.

With a trap using magnetic fields they captured eight calcium ions, lined them up, and set them up in "W states" using a complicated laser technology. A quantum byte with eight ions provides a computing matrix of 65,536 (0-255 x 0-255) elements that are mostly independent. It is suggested that the method should be scalable so that the number of ions could be increased. This experiment proves that the kind of ion traps used in Innsbruck are the most promising technology for the realization of large computing matrices.

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