Electric field manipulation enhanced by strong spin-orbit coupling: promoting rare-earth ions as qubits

Quantum information processing based on magnetic ions has potential for applications as the ions can be modified in their electronic properties and assembled by a variety of chemical methods. For these systems to achieve individual spin addressability and high energy efficiency, we exploited the electric field as a tool to manipulate the quantum behaviours of the rare-earth ion which has strong spin-orbit coupling. A Ce:YAG single crystal was employed with considerations to the dynamics and the symmetry requirements. The Stark effect of the Ce³⁺ ion was observed and measured. When demonstrated as a quantum phase gate, the electric field manipulation exhibited high efficiency which allowed up to 57 π/2 operations before decoherence with optimized field direction. It was also utilized to carry out quantum bang-bang control, as a method of dynamic decoupling, and the refined Deutsch-Jozsa algorithm. Our experiments highlighted rare-earth ions as potentially applicable qubits because they offer enhanced spin-electric coupling which enables high-efficiency quantum manipulation.     

资产减值准备与利润操纵

资产减值准备的计提对提高会计信息质量起着十分重要的作用,但在计提的过程中,利用减值准备进行利润操纵已成为必须解决的问题.本文将上市公司分为亏损和盈利两类,通过对上市公司利用资产减值准备操纵利润的现象透析,分析了上市公司频繁利用资产减值造假的原因,并提出现阶段有效防止上市公司利用资产减值准备造假的对策.     

寄生蜂作用于寄主的内部生理机制

寄生蜂在产卵的同时，常将一些特殊因子注射进寄主体内，从而对寄主的生长发育产生一定的调控作用．重点概述了寄生蜂作用于寄主的４个主要内部因子，即毒液、多态ＤＮＡ病毒、畸形细胞和寄生蜂幼虫分泌物．介绍了寄生蜂对寄主生长发育的调控，即发育同步性的调控、营养代谢的调控以及激素的调控     

浅谈权力监督制约机制

腐败行为产生的根本原因在于权力运作的失范。建立和完善权力运作的监督制约机制可以规范权力运作行为，增强监督活力，从而有效地惩治腐败。     

物理问题的符号处理方法

阐述用计算机对物理学问题进行符号处理的概念和方法，并论述使用个人计算机上的软件工具解析处理线性方程组和非线性微分方程物理问题的方法     

试析采用大树对乒乓球运动的影响

2000年2月23日，国际乒联代表大会式通过大球议案，并决定从2000年10月1日起改用大球。本探讨了大球与小球的不同，它对技战术的影响，对我国乒乓球王国地位的影响。     

通过自旋进动量子点的自旋相关的隧穿

Spin-polarized transport through a precessing magnetic spin coupled to ferromagnetic electrodes is studied using a non-equilibrium Green＇s function approach. The characteristic of conductance is obtained at zero temperature. We find that competition between spin-exchange interaction on the spin site and spin-orbit interaction in the barriers dominates the resonant behavior of conductance. In a parallel configuration, conductance peaks have identical amplitude. With the angle θ increasing, the width of resonant peaks is broadened or narrowed for different spin coherent states. In an anti-parallel case, spin-flip tunneling in the barriers will essentially enhance amplitude of the conductance peak.     

《献给艾米莉的玫瑰》叙事艺术论析

威廉·福克纳的短篇小说《献给艾米莉的玫瑰》以其怪异、恐怖的情节描写了一个没落贵族女性的爱情悲剧,借此揭示美国南方在南北战争之后的社会大变革中所经历的巨变。作者独具特色的叙事手法,成功地展现了作品的主题及思想内涵。     

Semiconductor quantum computation

Semiconductors, a significant type of material in the information era, are becoming more and more powerful in the field of quantum information. In recent decades, semiconductor quantum computation was investigated thoroughly across the world and developed with a dramatically fast speed. The research varied from initialization, control and readout of qubits, to the architecture of fault-tolerant quantum computing. Here, we first introduce the basic ideas for quantum computing, and then discuss the developments of single- and two-qubit gate control in semiconductors. Up to now, the qubit initialization, control and readout can be realized with relatively high fidelity and a programmable two-qubit quantum processor has even been demonstrated. However, to further improve the qubit quality and scale it up, there are still some challenges to resolve such as the improvement of the readout method, material development and scalable designs. We discuss these issues and introduce the forefronts of progress. Finally, considering the positive trend of the research on semiconductor quantum devices and recent theoretical work on the applications of quantum computation, we anticipate that semiconductor quantum computation may develop fast and will have a huge impact on our lives in the near future.     

汉语诗学观念对朱生豪翻译的影响

译入语内的诗学是翻译活动中一个重要的文化操纵因素,汉语诗学是一个多元的、不断演变的、较为独立的文学观念总和,译者和读者仅仅是片面地掌握并操纵诗学中的极其有限的规范。朱生豪使用白话翻译莎士比亚戏剧时,以包容的态度接受了欧化标准,并试图与传统诗学调和,采取了操纵改写策略,主要是顺从了汉语白话的诗学规范。