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111.
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A scheme is proposed to controll the decoherence of
three-level rf-SQUID qubit with asymmetric potential by designing an
external electric circuit for superconductive flux qubit. The
results show that it may not only raise the gate speed but also extend
decoherence time for a three-level structure. 相似文献
114.
The filter made up of two gratings performs as a two-dimensional non-spatial filtering. This paper reports that the volume Bragg gratings are fabricated by interfering two collimated coherent laser beams in photopolymer. Diffraction efficiency of a single grating is up to 78% in Bragg's condition, then a two-dimensional non-spatial filter, which consists of two volume Bragg gratings and a half-wave plate, enables the laser beam filtered in two dimensions with the diffraction efficiency of 54%. The Bragg's condition and effect of polarisation on performances of the two-dimension filter are also discussed. 相似文献
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当入射电磁波频率与金属微纳米结构中自由电子的集体振荡频率相当时,金属微纳米结构中激发表面等离激元共振,其共振电磁场被强束缚在亚波长尺度以下界面附近,使其具备极大的电磁场局域能力.这一效应可以极大程度地增强电磁波与物质的相互作用,在金属表面等离激元耦合体系中尤为明显.本文简述了表面等离激元耦合效应、模式耦合理论以及对应的结构耦合体系.另外,还介绍了一类典型耦合体系在光谱增强中的重要应用,主要包括增强折射率传感、表面增强红外吸收、表面增强拉曼散射、表面增强光学非线性效应等. 相似文献
117.
纳米晶交换耦合稀土永磁体α—Fe/Nd2Fe14B的居里温度及 … 总被引:4,自引:0,他引:4
从铁磁材料原子中电子间静电交换相互作用出发,结合Heisenberg铁磁性理论,从原子分子设计的角度,针对NdFeB基稀土永磁材料的晶体结构及原子占位特征,提出了提高居里温度TC的三条途径,在此基础上,利用熔体快淬工艺合成了具有高TC和磁性能的高温度稳定性的纳米晶稀土永磁体材料,并对其微结构及磁性能分别进行了表征和振动样品磁强计(VSM)的测试与讨论。 相似文献
118.
Highly charged ions (HCIs) have huge potential energy due to their high charge state. When a HCI reaches a solid surface, its potential energy is released immediately on the surface to cause a nano-scale defect. Thus, HCIs are expected to be useful for solid-surface modifications on the nano-scale. We investigate the defects on a highly oriented pyrolytic graphite (HOPG) surface induced by slow highly charged Ar^q+ ions with impact energy of 20-2000qeV with scanning probe microscopy (SPM). In order to clarify the role of kinetic and potential energies in surface modification, the nano-defects are characterized in lateral size and height corresponding to the kinetic energy and charge state of the HCIs. Both the potential energy and kinetic energy of the ions may influence the size of nano-defect. Since potential energy increases dramatically with increasing charge state, the potential energy effect is expected to be much larger than the kinetic energy effect in the case of extremely high charge states. This implies that pure surface modification on the nano-scale could be carried out by slow highly charged ions. The mean size of nano-defect region could also be controlled by selecting the charge state and kinetic energy of HCI. 相似文献
119.
Superconducting qubits are Josephson junction-based circuits that exhibit macroscopic quantum behavior and can be manipulated as artificial atoms.Benefiting from the well-developed technology of microfabrication and microwave engineering,superconducting qubits have great advantages in design flexibility,controllability,and scalability.Over the past decade,there has been rapid progress in the field,which greatly improved our understanding of qubit decoherence and circuit optimization.The single-qubit coherence time has been steadily raised to the order of 10 to 100μs,allowing for the demonstration of high-fidelity gate operations and measurement-based feedback control.Here we review recent progress in the coherence and readout of superconducting qubits. 相似文献
120.