Continuous weak measurement and feedback control of a solid-state charge qubit: A physical unravelling of non-Lindblad master equation

Conventional quantum trajectory theory developed in quantum optics is largely based on the physical unravelling of a Lindblad-type master equation, which constitutes the theoretical basis of continuous quantum measurement and feedback control. In this work, in the context of continuous quantum measurement and feedback control of a solid-state charge qubit, we present a physical unravelling scheme of a non-Lindblad-type master equation. Self-consistency and numerical efficiency are well demonstrated. In particular, the control effect is manifested in the detector noise spectrum, and the effect of measurement voltage is discussed.

Design of triangular lattice photonic crystals using genetic algorithms

Genetic Algorithms (GAs) were used to design triangular lattice photonic crystals with large absolute band-gap. Considering fabricating issues, the algorithms represented the unit cell with large pixels and took the largest absolute band-gap under the fifth band as the objective function. By integrating Fourier transform data storage mechanism, the algorithms ran efficiently and effectively and optimized a triangular lattice photonic crystal with scatters in the shape of 'dielectric-air rod'. It had a large absolute band gap with relative width (ratio of gap width to midgap) 23.8%.

New algorithms of the TSM and TOM methods for calibrating microwave test fixtures

Based on the conventional through-short-match (TSM) method, an improved TSM method has been proposed in this Letter. This method gives an analytical solution and has almost all the advantages of conventional TSM methods. For example, it has no phase uncertainty and no bandwidth limitation. The experimental results show that the accuracy can be significantly improved with this method. The proposed theory can be applied to the through-open-match (TOM) method. (C) 2002 Wiley Periodicals. Inc.

弱互模拟等价类算法改进

大量的硬件和软件系统广泛应用在一些重要的领域，在许多情况下错误和失效是不可接受的。需要提供方法来检验软硬件的正确性，增强我们对软硬件系统的信心。形式化验证提供了提高软硬件可靠性的方法。 互模拟等价类和弱互模拟等价类可以用来降低形式化验证中模型的规模。弱互模拟等价类有两种算法：一种是先计算迁移关系的自反传递闭包，然后调用互模拟等价类的算法。另一种是作为IGPTPartEF的一个特例，直接在原图上用划分精化的方法计算。针对这些计算弱互模拟等价类的算法，我们提出两种改进算法。 首先，我们观察到有些状态在划分精化的过程中不会被再次切分，可以事先将它们归类到一个组，在划分精化过程中以这些组为基本单位进行切分，可以在很大程度上减小算法花费的时间。我们用该思想给设计出了改进算法一。 然后，我们观察在Paige-Tarjan算法中引入了“处理比较小的一半”的思想来改进计算互模拟等价类的算法，它使得计算互模拟等价类的算法的时间复杂度从O(mn)（其中m是边数，n是顶点数）改进到O(mlgn)，而在前面所述的弱互模拟等价类算法中并没有引入“处理比较小的一半”。我们引入这一思想，设计出了改进算法二。 之后，我们设计实现了原型工具，并进行了数据实验来证实算法在时间上与原算法相比有明显改进。