Internet of Lamps for Future Ubiquitous Communications:Integrated Sensing,Hybrid Interconnection,and Intelligent Illumination

The ubiquitous deployment and restricted consumption are the requirements restricting the development of Internet of Things.Thus,a promising technology named Internet of Lamps(Io L)is discussed in this paper to address these challenges.Compared with other communication networks,the remarkable advantage of Io L is that it can make full use of the existing lighting networks with sufficient power supply.The lamps can be connected to the Internet through wired power line communication and/or wireless communication,while the integration of integrated sensing,hybrid interconnection,and intelligent illumination is realized.In this paper,the Io L is discussed from three aspects including sensing layer,network layer,and application layer,realizing the comprehensive upgrade based on the conventional communication and illumination systems.Meanwhile,several novel technologies of Io L are discussed based on the requirements of sensing,communication,and control,which have put forward practical solutions to the issues faced by Io L.Moreover,the challenges and opportunities for Io L are highlighted from various parts of the system structure,so as to provide future insights and potential trends for researchers in this field.

Simulation and Characterization of Aluminium Three-Dimensional Resonator for Quantum Computation

We present the simulation and characterization of several aluminium three-dimensional （31）） resonators, which can be used for superconducting quantum computation. By changing the conductivity of the aluminium in a high frequency structure simulator, the loaded quality factor at room temperature and base temperature （20 inK） can be simulated. From S21 measurement, we can characterize the properties of the resonators. The simulated and experimental results can be fitted well by exponential equations.

Single and Double Superconducting Coplanar Waveguide Resonators

Transmission characteristics of single and double coplanar waveguide(CPW)resonators are simulated.The crosstalk of two CPW resonators located on the same chip is observed in simulation as well as in low temperature measurement results.The crosstalk behaves as exponential attenuation versus the distance between two resonators.

Charge-Related SQUID and Tunable Phase-Slip Flux Qubit

A phase-slip flux qubit, exactly dual to a charge qubit, is composed of a superconducting loop interrupted by a phase-slip junction. We propose a tunable phase-slip flux qubit by replacing the phase-slip junction with a charge-related superconducting quantum interference device （SQUID） consisting of two phase-slip junctions connected in series with a superconducting island. This charge-SQUID acts as an effective phase-slip junction controlled by the applied gate voltage and can be used to tune the energy-level splitting of the qubit. In addition, we show that a large inductance inserted in the loop can reduce the inductance energy and consequently suppress the dominating flux noise of the phase-slip flux qubit. This enhanced phase-slip flux qubit is exactly dual to a transmon qubit.

Elastic Multiple Kernel Learning

(MKL ) 多重核学习被建议处理核熔化。MKL 听说线性联合几个核并且解决同时与联合的核联系的支持的向量机器(SVM ) 。MKL 的当前的框架鼓励核联合系数的稀少。核的重要部分什么时候是增进知识的，强迫稀少，趋于选择仅仅一些核并且可以忽略有用信息。在这份报纸，我们建议学习的有弹性的多重核(EMKL ) 完成适应的核熔化。EMKL 使用混合规则化功能损害稀少和非稀少。MKL 和 SVM 能被认为是 EMKL 的特殊情况。为 MKL 问题基于坡度降下算法，我们建议一个快算法解决 EMKL 问题。模拟数据集上的结果证明 EMKL 的表演有利地比作 MKL 和 SVM。我们进一步把 EMKL 用于基因集合分析并且得到有希望的结果。最后，我们学习比作另外的非稀少的 MKL 的 EMKL 的理论优点。

Dynamics and entanglement of a membrane-in-the-middle optomechanical system in the extremely-large-amplitude regime

The study of optomechanical systems has attracted much attention, most of which are concentrated in the physics in the smallamplitude regime. While in this article, we focus on optomechanics in the extremely-large-amplitude regime and consider both classical and quantum dynamics. Firstly, we study classical dynamics in a membrane-in-the-middle optomechanical system in which a partially reflecting and flexible membrane is suspended inside an optical cavity. We show that the membrane can present self-sustained oscillations with limit cycles in the shape of sawtooth-edged ellipses and exhibit dynamical multistability. Then, we study the dynamics of the quantum fluctuations around the classical orbits. By using the logarithmic negativity, we calculate the evolution of the quantum entanglement between the optical cavity mode and the membrane during the mechanical oscillation. We show that there is some synchronism between the classical dynamical process and the evolution of the quantum entanglement.

High-Density Stacked Ru Nanocrystals for Nonvolatile Memory Application

Stacked ruthenium （Ru） nanocrystals （NCs） are formed by rapid thermal annealing for the whole gate stacks and embedded in memory structure, which is compatible with conventional CMOS technology. Ru NCs with high density （3 × 10^12 cm-2）, small size （2 4nm） and good uniformity both in aerial distribution and morphology are formed. Attributed to the higher surface trap density, a memory window of 5.2 V is obtained with stacked Ru NCs in comparison to that of 3.5 V with single-layer samples. The stacked Ru NCs device also exhibits much better retention performance because of Coulomb blockade and vertical uniformity between stacked Ru NCs.

Autler-Townes Splitting in a △-Type Quantum Three-Level System

We observe the Autler-Townes splitting effect in a △-type quantum three-level system, using the lowest three levels of a SQUID-type Al/AlOx/Al transmon qubit embedded in a three-dimensional copper microwave cavity. A control tone at different strengths is applied in resonance with the transition between the first and second excited states, while the spectra between each of them and the ground state are probed by another microwave tone. The experimental result shows the difference between the two spectra, and fits well with the Lindblad master equation model.

Deterministic Quantum Key Distribution with Pulsed Homodyne Detection

In this paper, we propose a deterministic quantum communication protocol using weak coherent states and pulsed homodyne detection. In this protocol, the communication parties exchange their secret information deterministicaJly in two rounds. The devices and efficiency of the protocol are discussed respectively. We also show the security of the protocol against intercept-resend and Trojan-Horse eavesdropping attacks.

Nonvolatile Memory Characteristics with Embedded High Density Ruthenium Nanocrystals

Ruthenium （Ru） nanocrystals （NCs） embedded in SiO2 gate stacks are formed by rapid thermal annealing for the whole gate stacks and embedded in the memory structure, which is compatible with conventional CMOS technology. The devices exhibit a substantial and clockwise hysteresis in capacitance-voltage measurement. The Ru NCs exhibit high density （2 × 10^12cm^-2）, small size （2-4 nm） and good uniformity both in spatial distribution and morphology. The charging and long-term retention performances are explained by the Coulomb Blockade phenomena and the asymmetric electron tunnel barrier between the Ru NCs and the Si substrate, respectively.

Architecture Design of a Variable Length Instruction Set VLIW DSP

The cost of the central register file and the size of the program code limit the scalability of very long instruction word（VLIW） processors with increasing numbers of functional units.This paper presents the architectural design of a six-way VLIW digital signal processor（DSP） with clustered register files.The architecture uses a variable length instruction set and supports dynamic instruction dispatching.The one-level memory system architecture of the processor includes 16-KB instruction and data caches and 16-KB instruction and data on-chip RAM.A compiler based on the Open64 was developed for the system.Evaluations show that the processor is suitable for high performance applications with a high code density and small program code size.

Automatic Identification of Customized Instruction Based on Multiple Attribute Decision-Making for Multi-Issue Architectures

This paper illustrates the importance of the configuration of function units and the change of an application’s critical path when using instruction set extension （ISE） with multi-issue architectures. This paper also presents an automatic identification approach for customized instruction without input/output number constraints for multi-issue architectures. The approach identifies customized instructions using multiple attribute decision-making based on the analysis of several attributes for each candidate node. Tests indicate that the approach achieves higher speedup ratios than previous approaches, as well as less area cost. In addition, this approach provides designers with multiple candidate designs.

Second-order magnetic field gradient-induced strong coupling between nitrogen-vacancy centers and a mechanical oscillator

We consider a cantilever mechanical oscillator(MO) made of diamond. A nitrogen-vacancy(NV) center lies at the end of the cantilever. Two magnetic tips near the NV center induce a strong second-order magnetic field gradient. Under coherent driving of the MO, we find that the coupling between the MO and the NV center is greatly enhanced. We studied how to generate entanglement between the MO and the NV center and realize quantum state transfer between them. We also propose a scheme to generate two-mode squeezing between different MO modes by coupling them to the same NV center. The decoherence and dissipation effects for both the MO and the NV center are numerically calculated using the present parameter values of the experimental configuration. We have achieved high fidelity for entanglement generation, quantum state transfer, and large twomode squeezing.

Experimental quantum simulation of Avian Compass in a nuclear magnetic resonance system

Avian magnetoreception is the capacity for avians to sense the direction of the Earth's magnetic field. Discovered more than forty years ago, it has attracted intensive studies over the years. One promising model for describing this capacity in avians is the widely used reference-and-probe model where radical pairs within the eyes of bird combines to form singlet and triplet quantum states.The yield depends on the angle between the Earth's magnetic field and the molecules' axis, hence the relative value of yield of the singlet state or triplet state enables avians to sense the direction. Here we report the experimental demonstration of avian magnetoreception in a nuclear magnetic resonance quantum information processor. It is shown clearly from the experiment that the yield of the singlet state attains maximum when it is normal to the Earth's magnetic field, and the experimental results agree with theory very well.

Formation of stacked ruthenium nanocrystals embedded in SiO_2 for nonvolatile memory applications

Two methods are proposed to fabricate stacked ruthenium （Ru） nanocrystals （NCs）： rapid thermal annealing （RTA） for the whole gate stacks, and RTA before each SiO2 layer deposition. The size and aerial density of Ru NCs are 2-4 nm and 3 × 10^12 cm^-2 for the former method, compared to 3-7 nm and 2 ×10^12 cm^-2 for the latter. Because of the higher surface trap density and more uniform electron tunneling path between upper and lower Ru NCs, a 5.2 V memory window and 1 V after a period of 10 years are observed in metal oxide semiconductor （MOS） capacitors fabricated by the former method, which are much better than 4.6 V and no window remaining after one year observed in the latter. The former method is compatible with conventional CMOS technology.

Two-Way Digital Video Transmission over Medium-Voltage Power-Lines Using Time-Domain Synchronous Orthogonal Frequency Division Multiplexing Technology

This paper describes field trials of two-way digital video transmissions over a 700-m long medium-voltage power cable using a frequency division duplex scheme. The purpose is to check the feasibility of using time-domain synchronous orthogonal frequency division multiplexing （TDS-OFDM） technology in powerline communication （PLC）. TDS-OFDM is the core technology in digital multimedia broadcasting-terrestrial （DMB-T）, developed by Tsinghua University for digital television terrestrial multimedia broadcast applications and successfully adopted in the Chinese Digital Terrestrial Television Broadcasting Standard. PLC systems are widely believed to be bandwidth or data throughput limited. However, the use of known pseudo random sequences as guard intervals for synchronization and channel estimation in TDS-OFDM greatly reduces the system overhead and increases the spectrum efficiency. These experiments show that TDS-OFDM is appropriate not only for broadcasting but also for PLC applications with appropriate modifications.

Preparation of pseudo-pure states for NMR quantum computing with one ancillary qubit

Quantum state preparation plays an equally important role as quantum operations and measurements in quantum information processing. The previous methods for initialization require either an exponential number of experiments, or cause signal reduction or place restrictions on molecular structures. In this study, we propose three types of quantum circuits for preparing the pseudo-pure states of(n-1) qubits in the n-coupled Hilbert space, which simply needs the assistance of one ancilla spin and two different experiments independent of n. Most importantly, our methods work well on homo-nuclear and hetero-nuclear molecules without the reduction of signals in the gradient field. As a proof-of-principle demonstration, we experimentally prepared the pseudo-pure states of heteronuclear 2-qubit and homonuclear 4-qubit molecules using a nuclear magnetic resonance quantum information processor.

Simplified model and experimental validation for ultraviolet single-scattering channels

For nonline-of-sight ultraviolet communication links, a simple and concise parametric expression （PE） of channel path loss is valuable for link performance analysis in typical scenarios. It is observed that the light energy in the scattering volume can be approximated using a line integral. Combining curve fitting for the scattering phase function and the mean value theorem of integrals, we propose a simple but highly accurate PE. It matches well with the Monte Carlo simulations for typical LED-based communication with small beam divergence （〈45°）; when the beam divergence is smaller than 10°, their differences are less than 1 dB in most geometrical conditions. The proposed PE also shows good consistency with our outdoor experimental measurements, and the reported experimental results in the literature.

Hierarchical Cache Directory for CMP

As more processing cores are integrated into one chip and feature size continues to shrink, the average access la- tency for remote nodes using directory-based coherence protocol becomes higher, which greatly impacts system performance. Previous techniques such as data replication and data migration optimize the performance of the requesting core, but offer little improvement for neighbor nodes. Other techniques such as in-transit optimization try to reduce latency at the cost of increased storage. This paper introduces hierarchical cache directory into CMP （chip multiprocessor）, which divides CMP tiles into multiple regions hierarchically, and combines it with data replication. A new directory organization is proposed to record the share status within a region and assist the regional home to complete operation efficiently. Simulation results show that for a 16-core CMP, compared to traditional directory, hierarchical cache directory reduces average access latency by 9% and on-chip network traffic by 34% on average with less storage. Theoretical analyses show that for a 2^n × 2^n tiled CMP, the average access latency in hierarchical cache directory asymptotically approaches a function that is independent of n, hence the architecture is highly scalable.

Erratum to: Efficient universal quantum channel simulation in IBM's cloud quantum computer [Sci. China-Phys. Mech. Astron.61, 070311(2018)]

In this work,Shi-Jie Wei and Tao Xin contributed equally to this work.This annotation for the contribution was omitted in the original publication of this paper .It can be confirmed in the previous arXiv version .Hence,The sentence "ShiJie Wei and Tao Xin contributed equally to this work."should be added.