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Laue晶体单色器常用于单色化高能X射线(>50 keV),通过对其晶片压弯可以实现高能光束聚焦。晶片压弯过程中会不可避免地产生扭曲,从而影响单色器的工作效率。利用波动光学仿真的方法,分析弯晶面形扭曲对Laue晶体单色器性能的影响,并提出一种角位移微调轴角装置,用来消除这种扭曲。该装置基于直梁型柔性铰链,利用叠加原理和对称结构。利用有限元方法分析了该装置的力学性能。分析结果表明,轴角装置的转角范围为±2°时,其转动中心最大偏移为20 μm,实现了角位移分辨率好于1″,动态范围达到104,达到设计目标。 相似文献
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本文介绍浸泡法制备基于滤纸的SERS基底,并分析滤纸SERS基底表面银纳米粒子(AgNP)的分布与浸泡时间的关系。以精浆为检测对象,相比于514nm波长激发,785nm激发可获得更好的光谱数据,同时还比较了该波长激发下精浆的常规拉曼光谱与SERS光谱。更为重要的是,通过采用精浆中654cm-1谱峰强度评估不同浸泡时间下(6h,12h,24h)滤纸SERS基底的增强性能和测量结果的重复性。实验结果表明,12h浸泡获得的滤纸SERS基底表面具有均匀的AgNP分布,在785nm波长激发下,纸基SERS基底可提供增强效果及光谱重复性俱佳的精浆SERS光谱。 相似文献
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We study the electron states on lateral double quantum dots coupled in parallel. The charge stability diagrams are given in terms of the gate voltages of both dots. We discover that the two electron states translate from separated states to coupled states continuously by increasing the inter-dot coupling strength. Our results demonstrate that the parallel-quantum-dot tunability bodes well for future quantum computing applications. 相似文献
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Thirty years of effort in semiconductor quantum dots has resulted in significant developments in the control of spin quantum bits(qubits). The natural two-energy level of spin states provides a path toward quantum information processing. In particular, the experimental implementation of spin control with high fidelity provides the possibility of realizing quantum computing. In this review, we will discuss the basic elements of spin qubits in semiconductor quantum dots and summarize some important experiments that have demonstrated the direct manipulation of spin states with an applied electric field and/or magnetic field. The results of recent experiments on spin qubits reveal a bright future for quantum information processing. 相似文献
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在超导微波谐振腔耦合量子比特的杂化器件中,可利用超导材料动态电感随直流电流变化的特性,调节谐振腔的频率,进而匹配量子比特的频率.为抑制引入直流偏置电极导致的微波信号泄漏,在可调腔中加入滤波器是一种有效的方案.本研究以滤波器为切入点,运用计算机模拟,开发了原有“王”字型滤波器新的工作模式,并在实验上制作了可调超导微波谐振腔.测试结果表明,谐振腔的品质因子可达7800,阻抗约1700欧姆,谐振腔的频率可随直流电流发生明显变化,最大变化量可达26 MHz. 相似文献
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Charge noise acting on graphene double quantum dots in circuit quantum electrodynamics architecture
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We investigate the dephasing mechanisms induced by the charge noise and microwave heating effect acting on a graphene double quantum dot(DQD) capacitively coupled to a microwave resonator. The charge noise is obtained from DC transport current, and its contribution to dephasing is simultaneously determined by the amplitude response of the microwave resonator. A lowfrequency 1/f-type noise is demonstrated to be the dominant factor of the dephasing of graphene DQD. Furthermore, when the applied microwave power is larger than-90 d Bm, the dephasing rate of graphene DQD increases rapidly with the increase of microwave power, and fluctuates slightly with the applied microwave power smaller than-90 d Bm. Our results can be applied to suppress the impeditive influence on the dephasing of graphene-based devices associated with microwave input in the perspective investigations. 相似文献
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A double quantum dot defines a qubit by a two-level system. The coupling between two qubits induces a double two-level system into a four-level system. We study experimentally the coupling between two capacitive coupled GaAs/AlGaAs double quantum dots while tuning the energy detuning of each double quantum dot simultaneously. Applying microwave photons (at a frequency of 20 GHz) on this system and observing the resonance tunneling with a quantum point contact detector, we obtain an excitation spectrum which is consistent with the numerical simuIation result of a coupled two-qubit Hamiltonian. This study demonstrates that a double quantum dot can be exploited as an extraordinary platform for controlled quantum gates. 相似文献