1999/10/31 by Jonathan A. Jones, J. A. Jones, Vlatko Vedral +5 · 20 citations
Chemistry · Computer Science · Physics and Astronomy · #Advanced NMR Techniques and Applications #Molecular spectroscopy and chirality #Quantum Computing Algorithms and Architecture #quant-ph
paper · pdf · doi:10.1038/35002528
published as Nature 403 869-871 (2000) · Minor additions at request of referees. 4 pages revtex including 2 figures (1 eps). Nature in press
arxiv created 2000/01/05 · openalex publication_date 2000/02/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/02
The experimental realisation of the basic constituents of quantum information processing devices, namely fault-tolerant quantum logic gates, requires conditional quantum dynamics, in which one subsystem undergoes a coherent evolution that depends on the quantum state of another subsystem. In particular, the subsystem may acquire a conditional phase shift. Here we consider a novel scenario in which this phase is of geometric rather than dynamical origin. As the conditional geometric (Berry) phase depends only on the geometry of the path executed it is resilient to certain types of errors, and offers the potential of an intrinsically fault-tolerant way of performing quantum gates. Nuclear Magnetic Resonance (NMR) has already been used to demonstrate both simple quantum information processing and Berry's phase. Here we report an NMR experiment which implements a conditional Berry phase, and thus a controlled phase shift gate. This constitutes the first elementary geometric quantum computation.