Entanglement-Enhanced Two-Photon Delocalization in a Coupled-Cavity Array

We study the transport properties of two entangled photons which are initially injected into two nearest-neighbor coupling cavities in an one-dimensional coupled-cavity array （CCA）. It is found that photonic transport dynamics in the two-photon CCA exhibits the entanglement-enhanced two-photon delocalization phenomenon. It is shown that the CCA can realize the localization-to-delocalization transition for two entangled photons.

Design of a re-entrant double-staggered ladder circuit for V-band coupled-cavity traveling-wave tubes

The re-entrant double-staggered ladder slow-wave structure is employed in a high-power V-band coupled-cavity traveling-wave tube. This structure has a wide bandwidth, a moderate interaction impedance, and excellent thermal dissipation properties, as well as easy fabrication. A well-matched waveguide coupler is proposed for the structure. Combining the design of attenuators, a full-scale three-dimensional circuit model for the V-band coupled-cavity traveling- wave tube is constructed. The electromagnetic characteristics and the beam wave interaction of this structure are investigated. The beam current is set to be 100 mA, and the cathode voltage is tuned from 16.8 kV to 15.8 kV. The calculation results show that this tube can produce a saturated average output power over 100 W with an instantaneous bandwidth greater than 1.25 GHz in the frequency ranging from 58 GHz to 62 GHz. The corresponding gain and electronic efficiency can reach over 32 dB and 6.5%, respectively.

Study of a rectangular coupled cavity extended interaction oscillator in sub-terahertz waves

An extended interaction oscillator （EIO） generating 120 GHz wave in sub-terahertz waves is studied by using the three-dimensional electromagnetic simulation software CST and PIC codes. A rectangular reentrant coupled-cavity is proposed as the slow-wave structure of EIO. By CST, the circuit parameters including frequency-phase dispersion, interaction impedance and characteristic impedance are simulated and calculated. The operation mode of EIO is chosen very close to the point where βL = 2π with corresponding frequency 120 GHz, the beam voltage 12 kV and the dimensions of the cavity with the period 0.5mm, the height 3mm and the width 1.4mm. Simulation results of beam-wave interaction by PIC show that the exciting frequency is 120.85 GHz and output peak power 465 W with 12-period coupled-cavity with the perveance 0.17 μP. Simulation results indicate that the EIO has very wide range of the operation voltage.

Entanglements in a coupled cavity–array with one oscillating end-mirror

We theoretically investigate the entanglement properties in a hybrid system consisting of an optical cavity-array coupled to a mechanical resonator. We show that the steady state of the system presents bipartite continuous variable entanglement in an experimentally accessible parameter regime. The effects of the cavity-cavity coupling strength on the bipartite entanglements in the field-mirror subsystem and in the field-field subsystem are studied. We further find that the entanglement between the adjacent cavity and the movable mirror can be entirely transferred to the distant cavity and mirror by properly choosing the cavity detunings and the coupling strength in the two-cavity case. Surprisingly, such a remote macroscopic entanglement tends to be stable in the large coupling regime and persists for environment temperatures at above 25 K in the three-cavity case. Such optomechanical systems can be used for the realization of continuous variable quantum information interfaces and networks.

Entanglement and nonlocality in a coupled-cavity system

No instrument is able to measure directly the quantum entanglement of a system. However, both theory and experiment, following the well-known Bell inequality, reveal the existence of the entanglement phenomenon in quantum mechanics. To examine the characterization of quantum entanglement, here we present a two-site cavity system, in which each cavity contains a Λ-type three-level atom and the two sites are identical and coupled with each other. We investigate and calculate the bipartite entanglement entropy of the system for the ground states. For photons of different types, corresponding to the two ground states of the atom, we investigate the correlations and violation of the Bell inequality.

Cell-type continuous electromagnetic radiation system generating millimeter waves for active denial system applications

The cell-type continuous electromagnetic radiation system is a demonstration device capable of generating high-power millimeter electromagnetic waves of a specific wavelength and observing their effects on living organisms.It irradiates a biological sample placed in a 30×30×50 cm^(3)cell with electromagnetic waves in the 3.15-mm-wavelength region(with an output of≥1 W)and analyzes the temperature change of the sample.A vacuum electronic device-based coupled-cavity backward-wave oscillator converts the electron energy of the electron beam into radiofrequency(RF)energy and radiates it to the target through an antenna,increasing the temperature through the absorption of RF energy in the skin.The system causes pain and ultimately reduces combat power.A cell-type continuous electromagnetic radiation system consisting of four parts—an electromagnetic-wave generator,a highvoltage power supply,a test cell,and a system controller—generates an RF signal of≥1 W in a continuous waveform at a 95-GHz center frequency,as well as a chemical solution with a dielectric constant similar to that of the skin of a living organism.An increase of 5°C lasting approximately 10 s was confirmed through an experiment.

中国人口预期寿命预测的Double-Gap方法及其改进

文章通过引入灰色预测GM(1,1)模型改进Double-Gap方法对寿命差距进行建模,并将预测结果与传统Double-Gap方法、Lee-Carter模型和贝叶斯分层模型进行比较,以探寻适合中国人口预期寿命预测的科学方法。研究结果表明:(1)从建模原理看,Double-Gap方法不仅能在建模中将中国人口预期寿命与人类最优表现预期寿命进行关联,还能避免Lee-Carter模型等间接预测法中死亡模式固定的缺陷,同时方法客观、可操作性较强。(2)从模型的拟合与短期预测效果看,改进Double-Gap方法具有较小的平均绝对百分误差,并能有效弥补Lee-Carter模型在人口预期寿命预测中出现的过拟合问题。(3)从模型长期预测效果看,Lee-Carter模型和贝叶斯分层模型在预测中国人口预期寿命时较为保守,而Double-Gap方法预测的中国人口预期寿命能保持与最优表现预期寿命之间的合理变动趋势,并且改进D-G方法预测的出生人口平均预期寿命增长趋势的斜率值小于传统D-G方法,能够更好地反映出人口死亡率降低到一定程度后寿命增长减速的趋势。