Quantum computing in molecular magnets
Quantum computing in molecular magnets
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DOI：
10.1038/35071024
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发表时间：
2001-04-12
期刊：
影响因子：
64.8
通讯作者：
Loss, D
中科院分区：
文献类型：
--
作者：
Leuenberger, MN;Loss, D
肖尔和格罗弗证明，利用量子力学的并行性，量子计算机可以在分解数字(1)和搜索数据库(2)方面胜过任何经典计算机。Shor算法需要多粒子系统的叠加和纠缠(3)，而单粒子量子态的叠加对Grover算法(4)来说就足够了。最近，后者已经成功地实现(5)使用里德伯原子。在这里，我们提出了使用分子磁体（6-10）的Grover算法的实现，分子磁体是具有大自旋的固态系统；它们的自旋本征态使它们成为单粒子系统的自然候选者。我们从理论上证明了分子磁体可以用来构建基于Grover算法的密集和高效的存储设备。特别地，一个单晶可以作为动态随机存取存储器装置的存储单元。快速电子自旋共振脉冲可用于解码和读出最多10(5)个存储数字，访问时间短至10（-10）秒。结果表明，采用Fe-8和Mn-12分子磁体是可行的。
Shor and Grover demonstrated that a quantum computer can outperform any classical computer in factoring numbers(1) and in searching a database(2) by exploiting the parallelism of quantum mechanics. Whereas Shor's algorithm requires both superposition and entanglement of a many-particle system(3), the superposition of single-particle quantum states is sufficient for Grover's algorithm(4). Recently, the latter has been successfully implemented(5) using Rydberg atoms. Here we propose an implementation of Grover's algorithm that uses molecular magnets(6-10), which are solid-state systems with a large spin; their spin eigenstates make them natural candidates for single-particle systems. We show theoretically that molecular magnets can be used to build dense and efficient memory devices based on the Grover algorithm. In particular, one single crystal can serve as a storage unit of a dynamic random access memory device. Fast electron spin resonance pulses can be used to decode and read out stored numbers of up to 10(5), with access times as short as 10(-10) seconds. We show that our proposal should be feasible using the molecular magnets Fe-8 and Mn-12.