Chiaverini J, Britton J, Leibfried D, Knill E, Barrett M D, Blakestad R B, Itano W M, Jost J D, Langer C, Ozeri R, Schaetz T, Wineland D J
National Institute of Standards and Technology, Boulder, CO 80305, USA.
Science. 2005 May 13;308(5724):997-1000. doi: 10.1126/science.1110335.
We report the implementation of the semiclassical quantum Fourier transform in a system of three beryllium ion qubits (two-level quantum systems) confined in a segmented multizone trap. The quantum Fourier transform is the crucial final step in Shor's algorithm, and it acts on a register of qubits to determine the periodicity of the quantum state's amplitudes. Because only probability amplitudes are required for this task, a more efficient semiclassical version can be used, for which only single-qubit operations conditioned on measurement outcomes are required. We apply the transform to several input states of different periodicities; the results enable the location of peaks corresponding to the original periods. This demonstration incorporates the key elements of a scalable ion-trap architecture, suggesting the future capability of applying the quantum Fourier transform to a large number of qubits as required for a useful quantum factoring algorithm.
我们报告了在一个分段多区阱中限制的三个铍离子量子比特（二能级量子系统）的系统中实现半经典量子傅里叶变换的情况。量子傅里叶变换是肖尔算法中关键的最后一步，它作用于量子比特寄存器以确定量子态振幅的周期性。因为此任务仅需要概率振幅，所以可以使用更高效的半经典版本，对于该版本仅需要基于测量结果的单量子比特操作。我们将该变换应用于几个不同周期性的输入态；结果能够定位与原始周期相对应的峰值。此演示包含了可扩展离子阱架构的关键要素，表明未来有能力根据有用的量子因式分解算法的要求将量子傅里叶变换应用于大量量子比特。
