Schreodinger cats and their power for quantum information processing

Gilchrist, A. ; Nemoto, Kae ; Munro, William J. ; Ralph, T.C. ; Glancy, S. ; Braunstein, Samuel L:. ; Milburn, G.J.

HP Development Company

关键词: quantum information;    Schreodinger cat states;    quantum metrology;    coherent quantum;    quantum gates;    conditional measurements;   

RP-ID  :  HPL-2003-240

学科分类：计算机科学（综合）

美国|英语

来源: HP Labs

【 摘 要 】

We outline a toolbox comprised of passive optical elements, single photon detection and superpositions of coherent states (Schreodinger cat states). Such a toolbox is a powerful collection of primitives for quantum information processing tasks. We illustrate its use by outlining a proposal for universal quantum computation. We utilize this toolbox for quantum metrology applications, for instance weak force measurements and precise phase estimation. We show in both these cases that a sensitivity at the Heisenberg limit is achievable. Notes: Alexei Glichrist, T.C. Ralph and Gerard Milburn, Centre for Quantum Computer Technology and Department of Physics, University of Queensland, QLD 4072, Brisbane, Australia Kae Nemoto, National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan Scott Glancy, Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA Samuel L. Braunstein, Computer Science, York University, York YO10 5DD, UK