Implementation of a Quantum Search Algorithm on a Nuclear Magnetic Resonance Quantum Computer
Implementation of a Quantum Search Algorithm on a Nuclear Magnetic Resonance Quantum Computer
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发表时间：
1998
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通讯作者：
Jonathan A. Jones;M. Mosca;R. H. Hansen
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作者：
Jonathan A. Jones;M. Mosca;R. H. Hansen
用经典计算机模拟量子力学系统似乎是一个计算上难以解决的问题。1982年，费曼推翻了这一观察，提出量子力学系统的信息处理能力远大于相应的经典系统，因此可以用来实现一种新型的强大计算机。1985年，多伊奇描述了量子力学图灵机，表明量子计算机确实可以建造。从那时起，这一领域就有了广泛的研究，但尽管理论已经相当好地理解了，但实际上构建量子计算机被证明是极其困难的，只有两种方法被用来证明量子逻辑门：离子阱和核磁共振（NMR）。6 NMR量子计算机先前已被用于演示解决两位多伊奇问题的量子算法。[8]在这里，我们展示了如何使用这样的计算机来实现一种最初由Grover开发的快速量子搜索算法。[10]在其他应用中，Grover的算法能够在二元函数的域上进行极其快速的搜索，以找到满足该函数的元素（即，该函数的值为1）。如果满足的值的数量是事先已知的，这种方法更简单，并且当域中恰好有四分之一的元素满足函数时特别简单。该算法可以使用具有两个量子比特（qubit）的计算机来搜索两个比特域，其中四个元素中的一个满足函数。这个域的经典搜索将需要1到3之间的值
The simulation of quantum mechanical systems with classical computers appears to be a computationally intractable problem. In 1982 Feynman reversed this observation, suggesting that quantum mechanical systems have an information processing capability much greater than that of corresponding classical systems, and thus could be used to implement a new type of powerful computer. In 1985 Deutsch described a quantum mechanical Turing machine, showing that quantum computers could indeed be constructed. Since then there has been extensive research in this field, but while the theory is fairly well understood actually building a quantum computer has proved extremely difficult, and only two methods have been used to demonstrate quantum logic gates: ion traps, 4 and nuclear magnetic resonance (NMR). 6 NMR quantum computers have previously been used to demonstrate quantum algorithms to solve the two bit Deutsch problem. 8 Here we show how such a computer can be used to implement a fast quantum search algorithm initially developed by Grover. 10 Among other applications Grover’s algorithms enable an extremely rapid search over the domain of a binary function to find elements for which this function is satisfied (that is, the function has the value 1). This approach is simpler if the number of satisfying values is known beforehand, and is particularly simple when precisely one quarter of the elements in the domain satisfy the function. The algorithm can be demonstrated using a computer with two quantum bits (qubits) to search a two bit domain in which one of the four elements satisfies the function. A classical search of this domain would require between 1 and 3