Quantum oscillations in two coupled charge qubits

A practical quantum computer, if built, would consist of a set of coupled two-level quantum systems (qubits). Among the variety of qubits implemented, solid-state qubits are of particular interest because of their potential suitability for integrated devices. A variety of qubits based on Josephson junctions have been implemented; these exploit the coherence of Cooper-pair tunnelling in the superconducting state. 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.     

含Si－H功能键聚硅氧烷／聚芳砜嵌段共聚物膜性能研究

研究了聚硅氧烷／聚砜二元嵌段共聚物（ＰＭＳ／ＰＳＦ）的成膜行为和膜强度，讨论ＰＭＳ、吡啶侧基、Ｃｏ（Ｓａｌｅｎ）含量对它们的影响；测定了膜对空气的透过率和富氧率，总结出该膜的富氧率随ＰＭＳ含量、温度、压力改变的变化规律，当软硬段含量相近时，ＰＭＳ／ＰＳＦ膜的各种特性最好，在本实验条件下，ＰＭＳ／ＰＳＦ膜的最高富氧率达３６％。