基于光纤连接的腔系统实现两比特离散量子傅立叶变换

提出了在外加经典场驱动的情况下,利用光纤连接的2个腔系统执行两比特离散量子傅立叶变换的方案.该方案通过发送2个原子交替通过一系列经典场和腔场来实现,而且该两比特方案可推广至N比特离散量子傅立叶变换.     

Time evolution of entanglement and bistability of two coupled quantum dots in a driven cavity

Abstract

The time evolution of entanglement between two quantum dots (QDs) trapped inside a cavity driven by a coherent quantized field is studied. In the presence of dissipation, entanglement shows many interesting features such as sudden death and revival, and finite steady state value after sudden death. We also investigate dependence of entanglement on dot variables and its relation to bistability. It is found that entanglement vanishes when the cavity field intensity approaches the upper branch of the bistability curve. When the cavity is driven by a modulated field in the presence of dissipation, it can periodically generate entanglement, which is much larger than the maximum value attained in the steady-state for this system but the dots are never fully entangled.     

WTO — a deterministic approach to 4-fermion physics

The program WTO, which is designed for computing cross sections and other relevant observables in the e⁺e⁻ annihilation into four fermions, is described. The various quantities are computed over both a completely inclusive experimental set-up and a realistic one, i.e. with cuts on the final state energies, final state angles, scattering angles and final state invariant masses. Initial state QED corrections are included by means of the structure function approach while final state QCD corrections are applicable in their naive formulation. A gauge restoring mechanism is included according to the Fermion-Loop scheme. The program structure is highly modular and particular care has been devoted to computing efficiency and speed.     

基于纠缠转换秘密共享一个任意两原子纠缠态

提出一个利用纠缠转换在腔QED中来实现秘密共享一个任意两原子纠缠态的方案.结果表明,随着控制者数量的增加,窃听者的成功机率降低.     

相位协变量子克隆的腔QED实现方案

提出一种1→2相位协变量子克隆的腔QED实现方案,该克隆过程是基于原子与两个高Q腔场的相互作用来实现的.腔场最初处于真空态.虽然该方案需要实现CNOT操作,但与其它方案相比该方案需要的操作更加简单方便,并且该方案里所使用的基本操作(受控量子门操作和经典场脉冲操作)都已经得到充分的验证.所以我们相信该方案能在实验上实现.     

Mechanizing set theory

Fairly deep results of Zermelo-Frænkel (ZF) set theory have been mechanized using the proof assistant Isabelle. The results concern cardinal arithmetic and the Axiom of Choice (AC). A key result about cardinal multiplications is =, where is any infinite cardinal. Proving this result required developing theories of orders, order-isomorphisms, order types, ordinal arithmetic, cardinals, etc.; this covers most of Kunen, Set Theory, Chapter I. Furthermore, we have proved the equivalence of 7 formulations of the Well-ordering Theorem and 20 formulations of AC; this covers the first two chapters of Rubin and Rubin, Equivalents of the Axiom of Choice, and involves highly technical material. The definitions used in the proofs are largely faithful in style to the original mathematics.     

无需直接Bell态测量的n-量子比特未知量子信息远程传输

量子信息传输过程需要实验上难以实现的直接Bell态测量,基于腔QED理论,让二能级原子与一个受强经典场驱动的大失谐腔场相互作用,可用单原子投影测量替代直接Bell态测量,以实现n-量子比特量子信息传输。引入十进制数来表示量子比特的量子态,给出了信息发送者的测量结果与信息接收者的幺正操作之间简单明了的一一对应关系,使复杂的多体问题简单化。     

利用腔QED技术实现特殊三粒子W态的隐形传送

提出一个在腔QED中实现特殊三粒子W态的隐形传送方案.在方案中用3个二粒子纠缠态作为量子通道,通过原子与腔及经典场之间的相互作用以及适当的幺正变换,以成功几率1实现了特殊三粒子W态的传送.此外,本方案不需要联合贝尔测量,对腔衰减和热场也不敏感.