Generation of multiple-particle cluster state via cavity QED

This paper proposes schemes for generating multiple-photon and multiple-atom cluster states, respectively. The schemes are based on the cavity input--output process and atomic or photonic states measurement, and the successful probabilities approach unity in the ideal case. The numerical simulations show that the produced multiple-particle cluster states have high fidelity even if the Lamb--Dicke condition is not satisfied. Some practical imperfections, such as atomic spontaneous emission and output coupling inefficiency, only decrease the success probability but exert no influence on the fidelity of generated multiple-particle cluster states. From the experimental point of view, smaller operation number and lack of need for individual addressing keeps the schemes easy to implement. These schemes may offer a promising approach to the generation of a large-scale cluster state.     

Teleportation of an arbitrary mixture of diagonal states of multiqudit

This paper proposes a scheme to teleport an arbitrary mixture of diagonal states of multiqutrit via classical correlation and classical communication. To teleport an arbitrary mixture of diagonal states of N qutrits, N classically correlated pairs of two qutrits are used as channel. The sender （Alice） makes Fourier transform and conditional gate （i.e., XOR（3） gate） on her qutrits and does measurement in appropriate computation bases. Then she sends N ctrits to the receiver （Bob）. Based on the received information, Bob performs the corresponding unitary transformation on his qutrits and obtains the teleported state. Teleportation of an arbitrary mixture of diagonal states of multiqudit is also discussed.     

Zero-dispersion waveguide of sub-skin-depth terahertz plasmons using metallic nanowires

Global change in the dispersive behavior of terahertz （THz） plasmons on metal wires with wide radii ranging from 5 nm to 0.5 mm is systematically investigated. Through rigorous numerical calculations, we find that the dispersion of a metal wire with a radius of 5 nm increases by about 4-6 orders of magnitude compared with the case of a metallic wire with a radius of 0.5 mm. Zero-dispersion points appear when the frequency is lower than 3 THz, and the positions of the zero-dispersion points can shift with the frequency. Finally, we provide an explicit expression that agrees verv well with the numerical calculations.     

Cavity linewidth narrowing with dark-state polaritons

We present a quantum-theoretical treatment of cavity linewidth narrowing with intracavity electromagnetically induced transparency(EIT). By means of intracavity EIT, the photons in the cavity are in the form of cavity polaritons:bright-state polariton and dark-state polariton. Strong coupling of the bright-state polariton to the excited state induces an effect known as vacuum Rabi splitting, whereas the dark-state polariton decoupled from the excited state induces a narrow cavity transmission window. Our analysis would provide a quantum theory of linewidth narrowing with a quantum field pulse.     

基于光子晶体腔链的量子态传输及相位门的实现

研究了光子晶体腔链中任意两奇数节点间量子态传输及相位门实现的问题。发现在绝热条件下,通过求解原子和光子晶体腔链耦合模型的暗态,可实现一维光子晶体耦合腔链中两个腔之间二维量子态的传输及可控相位门。在量子态传输的过程中若原子与腔的耦合强度足够大,腔的激发态的布居数小到可以被忽略。最后讨论了腔链的长度与相位门保真度的关系以及腔链的长度、初态的制备、腔的衰减、原子与腔的耦合强度对量子态传输保真度的影响。     

Scattering of a single photon in a one-dimensional coupled resonator waveguide with a Λ-type emitter assisted by an additional cavity

We analyze the transport property of a single photon in a one-dimensional coupled resonator waveguide coupled with a Λ-type emitter assisted by an additional cavity. The reflection and transmission coefficients of the inserted photon are obtained by the stationary theory. It is shown that the polarization state of the inserted photon can be converted with high efficiency. This study may inspire single-photon devices for scalable quantum memory.     

Implementing entanglement teleportation via adiabatic passage

This paper proposes a scheme for implementing teleportation of an entangled state of two trapped atoms through adiabatic passage and photonic interference. The scheme is robust against certain noise such as atomic spontaneous emission and the detector inefficiency.     

有源和无源的无磁非互易研究进展

根据洛伦兹互易定理,在通常的光学系统中,交换信号源和探测器的位置后接收到的光信号不变。这为光路设计和分析带来了方便。在全光通信和量子网络中,需要有效地控制光信号的定向传输以避免反射光对信号的干扰、分离相向传输的光信号等,因此需要只允许光单向传输的非互易器件。以磁光隔离器为背景切入,简单介绍磁光领域的研究现状。重点从有源和无源两个方面对无磁非互易领域的发展进行综述,以展现量子光学在无磁非互易领域的重要应用。     

Generation of atomic Greenberger-Horne-Zeilinger states and cluster states through cavity-assisted interaction

This paper proposes a scalable scheme to generate n-atom GHZ states and cluster states by using the basic building block, i.e., a weak coherent optical pulse [α） being reflected successively from a single-atom cavity. In the schemes, coherent state of light is used instead of single photon source, homodyne measurement on coherent light is done kastead of single photon detection, and no need for individually addressing keeps the schemes easy to implement from the experimental point of view. The successful probabilities of our protocols approach unity in the ideal case.     

以学生为中心的物理基础课程教学改革

本文基于公共基础课程"大学物理"与专业基础课程"光学"的教学改革探索与实践,阐述在以"学生为中心"的教学理念下,针对物理基础课程的特点,进行教学过程的优化和教学模式的改革.大规模基础课程教学从整体引导和个别指导的有机结合着手、专业基础课程则从课堂封闭教学向开放教学的转变着手,以此促进学生的全员发展和个性发展,推进研究性学习模式的形成.