Quantum oscillations in two coupled charge qubits
Quantum oscillations in two coupled charge qubits
复制标题
DOI：
10.1038/nature01365
复制
发表时间：
2003-02-20
期刊：
影响因子：
64.8
通讯作者：
Tsai, JS
中科院分区：
文献类型：
--
作者：
Pashkin, YA;Yamamoto, T;Tsai, JS
一台实用的量子计算机（1）如果建成，将由一组耦合的两级量子系统（量子比特）组成。在实现的各种量子位中，固态量子位特别令人感兴趣，因为它们对集成器件的潜在适用性。基于约瑟夫森结（3，4）的各种量子比特已经实现（5-8）;这些利用了超导态中库珀对隧穿的相干性（5-10）。尽管在实现单个固态量子比特方面取得了明显的进展，但还没有多量子比特门的实验报告这是构建真实的量子计算机的基本要求。在这里，我们展示了由两个耦合电荷量子位组成的约瑟夫森电路。使用脉冲技术，我们相干地混合量子态并观察量子振荡，其光谱反映了量子比特之间的相互作用。我们的结果证明了耦合多个固态量子比特的可行性，并指出纠缠的两个量子比特的状态的存在。
A practical quantum computer(1), if built, would consist of a set of coupled two-level quantum systems (qubits). Among the variety of qubits implemented(2), solid-state qubits are of particular interest because of their potential suitability for integrated devices. A variety of qubits based on Josephson junctions(3,4) have been implemented(5-8); these exploit the coherence of Cooper-pair tunnelling in the superconducting state(5-10). Despite apparent progress in the implementation of individual solid-state qubits, there have been no experimental reports of multiple qubit gates-a basic requirement for building a real quantum computer. Here we demonstrate a Josephson circuit consisting of two coupled charge qubits. Using a pulse technique, we coherently mix quantum states and observe quantum oscillations, the spectrum of which reflects interaction between the qubits. Our results demonstrate the feasibility of coupling multiple solid-state qubits, and indicate the existence of entangled two-qubit states.