A Synthetic Two-Spin Quantum Bit: g-Engineered Exchange-Coupled Biradical Designed for Controlled-NOT Gate Operations
A Synthetic Two-Spin Quantum Bit: g-Engineered Exchange-Coupled Biradical Designed for Controlled-NOT Gate Operations
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DOI：
10.1002/anie.201204489
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发表时间：
2012-01-01
影响因子：
16.6
通讯作者：
Takui, Takeji
中科院分区：
文献类型：
--
作者：
Nakazawa, Shigeaki;Nishida, Shinsuke;Takui, Takeji
在过去的十年里，尽管分子电子自旋量子比特(量子比特)是许多物理量子比特中最新出现的，但一个迅速发展的量子计算和量子信息处理(QC和QIP)领域与化学有关。[1]提到化学和QC/QIP之间的联系，重要的是，最近的QC/QIP方法表明，从理论上讲，可以通过极大地增加QC/QIP的计算能力来评估分子性质的计算。[1A，2]当前的QC/QIP研究取得了广泛的进展，使用光子量子比特，[3]囚禁离子，[4]量子点，[5]和金刚石中具有氮空位色心的超导磁通量子比特的相干耦合系统。[6]有趣的是，基于金属络合物的新的物质自旋量子比特在分子磁性领域被提出。[7]我们提出了一种新的基于分子的电子自旋量子比特的体系结构，能够实现可控非(CNOT)量子门。为这样一台能够破解现代互联网服务中使用的RSA(公钥密码算法)的实用量子计算机构建多量子比特系统，被认为在未来十年仍是一个棘手的问题。因此，量子比特的可伸缩性是相关的。[8]所有现有的量子比特都面临着获得其可伸缩性的挑战。从合成化学的角度来看，劳埃德·S的建议似乎在为真正的量子计算机准备一些量子比特方面是可行的。[9]从化学的角度，对劳埃德·S模型提出了一个材料挑战，即合成嵌入开壳过渡金属离子的三链螺旋结构。[10]还利用失配的dna基骨方法，利用核酸之间的互补氢键，在所需位置的自由基构建一维电子自旋阵列。[11]电子自旋量子比特具有制备初始态的优点，与具有比电子自旋小103倍的旋磁比固有的低极化的核自旋量子比特的困难相比，[12]利用电子自旋和核自旋的优点，研究了电子自旋和核自旋量子比特的混合系统。[13]图1显示了设计为量子计算的基本单元的两个量子比特的双基1，它可以提供CNOT门操作，这些门本质上是组成通用量子门集合的重要门，以及定义明确的单量子比特操作。[14]双基1是{(2，2，6，6-四甲基哌啶-N-氧基-4-基)，5-二甲基苯甲酸酯-4-基)对苯二甲酸酯，其交换偶联极弱
The last decade has witnessed that a rapidly developing field of quantum computing and quantum information processing (QC and QIP) is linked to chemistry in spite of the fact that molecular electron spin qubits (quantum bits) are the latest arrival among many physical qubits.[1] Referred to the linkage between chemistry and QC/QIP, importantly, recent QC/QIP approaches have shown that calculations of molecular properties can be assessable in terms of enormously increased computational power of QC/QIP, from the theoretical side.[1a, 2] Current QC/QIP research makes extensive progress using photon qubits,[3] trapped ions,[4] quantum dots,[5] and coherent coupling systems of superconducting flux qubits with nitrogen-vacancy color centers in diamond.[6] Interestingly, novel matter spin qubits based on metal complexes have been proposed in the field of molecular magnetism.[7] We propose a novel architecture of molecule-based electron spin qubits capable of performing Controlled-NOT (CNOT) quantum gates. The build-up of the multi-qubit system for such a practical quantum computer that is capable of breaking an RSA (algorithm for public-key cryptography) cryptograph used in modern internet services is conceived of as still an intractable issue in a decade of years ahead. Thus the scalability of qubits is relevant.[8] All the existing qubits have faced a challenge of acquiring their scalability. Lloyd s proposal seems to be practical in preparing a number of qubits for true quantum computers from a synthetic chemistry viewpoint.[9] From the chemistry side, a materials challenge for Lloyd s model has been made to synthesize triple-stranded helicates embedding open-shell transition-metal ions.[10] A mismatched DNA-backbonebased approach has also been exploited to build up onedimensional electron spin arrays with the radicals at desired positions using complementary hydrogen bonds between nucleic acids.[11] Electron spin qubits have an advantage of the preparation of initialized states, contrasting with the difficulty of nuclear spin qubits with low polarization intrinsic to their gyromagnetic ratios 103 times smaller than that of an electron spin.[12] The hybrid systems of the electron spin and the nuclear spin qubits have been studied, using advantages of both the electron spin and nuclear spin.[13] Figure1 shows a two-qubit biradical 1 designed as a fundamental unit of quantum computing that can afford CNOT gate operations, which are essentially important gates to constitute a universal set of quantum gates together with well-defined single qubit operations.[14] Biradical 1 is {(2, 2, 6, 6-tetramethylpiperidin-N-oxyl-4-yl) 3, 5-dimethylbenzoate-4-yl} terephthalate, in which extremely weak exchange-coupling