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Advances in quantum dense coding [article]

Yu Guo, Bi-Heng Liu, Chuan-Feng Li, Guang-Can Guo
2019 arXiv   pre-print
Quantum dense coding is one of the most important protocols in quantum communication. It derives from the idea of using quantum resources to boost the communication capacity and now serves as a key primitive across a variety of quantum information protocols. Here, we focus on the basic theoretical ideas behind quantum dense coding, discussing its development history from discrete and continuous variables to quantum networks, then to its variant protocols and applications in quantum secure
more » ... ication. With this basic background in hand, we then review the main experimental achievements, from photonic qubits and qudits to optical modes, nuclear magnetic resonance, and atomic systems. Besides the state of the art, we finally discuss potential future steps.
arXiv:1904.12252v1 fatcat:ez3gd47h2vcejmnxtov3mtdhlu

Experimental test of the tradeoff relation in weak measurement [article]

Geng Chen, Yang Zou, Xiao-Ye Xu, Jian-Shun Tang, Yu-Long Li, Yong-Jian Han, Chuan-Feng Li, Guang-Can Guo Hai-qiao Ni, Ying Yu, Mi-feng Li, Guo-wei Zha, Zhi-Chuan Niu
2013 arXiv   pre-print
An upper bound between the information gain and state reversibility of weak measurement was first developed by Y. K. Cheong and S. W. Lee [Phys. Rev. Lett. 109, 150402 (2012)]. Their results are valid for arbitrary d-level quantum systems. In light of the commonly used qubit system in quantum information, a sharp tradeoff relation can be obtained. In this letter, this tradeoff relation is experimentally verified with polarization encoded single photons from a quantum dot. Furthermore, a
more » ... traversal of weak measurement operators is realized, and the mapping to the least upper bound of this tradeoff relation is obtained. Our results complement the theoretical work and provide a universal ruler for the characterization of weak measurements.
arXiv:1306.1027v1 fatcat:6kjwcf6oavdnxg7qujhcrawbbm

COVID-19 Asymptomatic Infection Estimation [article]

Yang Yu, Yu-Ren Liu, Fan-Ming Luo, Wei-Wei Tu, De-Chuan Zhan, Guo Yu, Zhi-Hua Zhou
2020 medRxiv   pre-print
Yu-Ren Liu, Yi-Qi Hu, Hong Qian, Yang Yu, and Chao Qian. Zoopt: Toolbox for derivative-free optimization. CoRR, abs/1801.00329, 2018. Yu-Ren Liu, Yi-Qi Hu, Hong Qian, and Yang Yu.  ...  ., 2019; Yu et al., 2016] . ZOOpt [Liu et al., 2018] is a python package for derivative-free optimization.  ... 
doi:10.1101/2020.04.19.20068072 fatcat:22eev3z7dfa55lsrwtihnmtb44

Lyapunov function for non-equilibrium transport processes [article]

Chuan-Jin Su, Yu-Chao Hua, Zeng-Yuan Guo
2022 arXiv   pre-print
Applying our theorem of Lyapunov function for parabolic-like transport processes, a Lyapunov function is expressed as G e = V X e • qdV = V k∇T • ∇T dV. ( 12 ) Guo et al.  ...  Least generalized entransy dissipation principle is proposed by Hua and Guo [14] , to extend the scope of the entransy concept to the case of temperature dependent thermal conductivity.  ... 
arXiv:2202.08001v1 fatcat:oaa3mq5pzreczmhjlz5r7cfaza

Simultaneous observation of quantum contextuality and quantum nonlocality

Xiao-Min Hu, Bi-Heng Liu, Jiang-Shan Chen, Yu Guo, Yu-Chun Wu, Yun-Feng Huang, Chuan-Feng Li, Guang-Can Guo
2018 Science Bulletin  
Quantum nonlocality and quantum contextuality are the most curious properties that change our understanding of nature, and were observed independently in recent decades. One important question is whether both properties can be observed simultaneously. In this paper, we show that in a qutrit-qutrit system we can observe quantum nonlocality and quantum contextuality at the same time. From the perspective of quantum information, our experiment proves in principle that the two resources, quantum
more » ... locality and quantum contextuality, can be utilized simultaneously.
doi:10.1016/j.scib.2018.06.018 fatcat:snkok3e6tfdnzetqzpzbxuo5pa

Experimental realisation of generalised qubit measurements based on quantum walks [article]

Yuan-yuan Zhao, Neng-kun Yu, Pawe Kurzynski, Guo-yong Xiang, Chuan-Feng Li, Guang-Can Guo
2015 arXiv   pre-print
We report an experimental implementation of a single-qubit generalised measurement scenario(POVM) based on a quantum walk model. The qubit is encoded in a single-photon polarisation. The photon performs a quantum walk on an array of optical elements, where the polarisation-dependent translation is performed via birefringent beam displacers and a change of the polarisation is implemented with the help of wave-plates. We implement: (i) Trine-POVM, i.e., the POVM elements uniformly distributed on
more » ... n equatorial plane of the Bloch sphere; (ii) Symmetric-Informationally- Complete (SIC) POVM; and (iii) Unambiguous Discrimination of two non-orthogonal qubit states.
arXiv:1501.05096v1 fatcat:losuodz7bzekxlls5p7okhj7ue

DEM/CFD modelling of the deposition of dilute granular systems in a vertical container

Shen Yu, Yu Guo, Chuan-Yu Wu
2009 Science Bulletin  
Chem Eng Sci, 2007, 62: 6423-6439[DOI] 4 Feng Y Q, Yu A B. Microdynamic modelling and analysis of the mixing and segregation of binary mixtures of particles in gas fluidization.  ... 
doi:10.1007/s11434-009-0474-y fatcat:7rw4yc2nhvawjepbkicciuplya

Compact Graph Structure Learning via Mutual Information Compression [article]

Nian Liu, Xiao Wang, Lingfei Wu, Yu Chen, Xiaojie Guo, Chuan Shi
2022 arXiv   pre-print
Graph Structure Learning (GSL) recently has attracted considerable attentions in its capacity of optimizing graph structure as well as learning suitable parameters of Graph Neural Networks (GNNs) simultaneously. Current GSL methods mainly learn an optimal graph structure (final view) from single or multiple information sources (basic views), however the theoretical guidance on what is the optimal graph structure is still unexplored. In essence, an optimal graph structure should only contain the
more » ... information about tasks while compress redundant noise as much as possible, which is defined as "minimal sufficient structure", so as to maintain the accurancy and robustness. How to obtain such structure in a principled way? In this paper, we theoretically prove that if we optimize basic views and final view based on mutual information, and keep their performance on labels simultaneously, the final view will be a minimal sufficient structure. With this guidance, we propose a Compact GSL architecture by MI compression, named CoGSL. Specifically, two basic views are extracted from original graph as two inputs of the model, which are refinedly reestimated by a view estimator. Then, we propose an adaptive technique to fuse estimated views into the final view. Furthermore, we maintain the performance of estimated views and the final view and reduce the mutual information of every two views. To comprehensively evaluate the performance of CoGSL, we conduct extensive experiments on several datasets under clean and attacked conditions, which demonstrate the effectiveness and robustness of CoGSL.
arXiv:2201.05540v1 fatcat:hio722ik45aeraxd76svzjhfkq

On Calibration of Modern Neural Networks [article]

Chuan Guo, Geoff Pleiss, Yu Sun, Kilian Q. Weinberger
2017 arXiv   pre-print
Confidence calibration -- the problem of predicting probability estimates representative of the true correctness likelihood -- is important for classification models in many applications. We discover that modern neural networks, unlike those from a decade ago, are poorly calibrated. Through extensive experiments, we observe that depth, width, weight decay, and Batch Normalization are important factors influencing calibration. We evaluate the performance of various post-processing calibration
more » ... hods on state-of-the-art architectures with image and document classification datasets. Our analysis and experiments not only offer insights into neural network learning, but also provide a simple and straightforward recipe for practical settings: on most datasets, temperature scaling -- a single-parameter variant of Platt Scaling -- is surprisingly effective at calibrating predictions.
arXiv:1706.04599v2 fatcat:ouwx5xxp5rc73o2nmsluedyi6e

Sensing mechanisms and applications of flexible pressure sensors

Xing-Yu Hou, Chuan-Fei Guo
2020 Wuli xuebao  
基于银纳米线电极-rGO敏感材料的柔性NO 2 气体传感器 Flexible nitrogen dioxide gas sensor based on reduced graphene oxide sensing material using silver nanowire electrode
doi:10.7498/aps.69.20200987 fatcat:subunptelzc5vfrihvn4h63bwq

Measurement-device-independent quantification of irreducible high-dimensional entanglement [article]

Yu Guo, Bai-Chu Yu, Xiao-Min Hu, Bi-Heng Liu, Yu-Chun Wu, Yun-Feng Huang, Chuan-Feng Li, Guang-Can Guo
2019 arXiv   pre-print
The certification and quantification of entanglement are of great importance in characterizing entangled systems. Recently it is pointed out that the quantum correlation of higher dimensional bipartite states can be simulated with a sequence of lower dimensional states and sequential measurements. Such scheme may render some entanglement tests unreliable---the observed entanglement may not be a genuine high-dimensional one. Here we show that a recently proposed quantitative
more » ... dependent entanglement witness protocol is naturally robust against such scheme, thus can be used as an irreducible high-dimensional entanglement quantifier and irreducible dimension witness. We then experimentally demonstrate this protocol on a 3-dimensional bipartite state, observing an entanglement that exceeds the bound when the cheating scheme with arbitrary 2-dimensional states is used. The result certifies our system is entangled in dimension (at least) d = 3.
arXiv:1901.00999v2 fatcat:2exeskien5brlntnbatbcc6zde

Orientational quantum revivals induced by a single-cycle terahertz pulse [article]

Chuan-Cun Shu, Qian-Qian Hong, Yu Guo, Niels E. Henriksen
2020 arXiv   pre-print
The phenomenon of quantum revivals resulting from the self-interference of wave packets has been observed in several quantum systems and utilized widely in spectroscopic applications. Here, we present a combined analytical and numerical study on the generation of orientational quantum revivals (OQRs) exclusively using a single-cycle THz pulse. As a proof of principle, we examine the scheme in the linear polar molecule HCN with experimentally accessible pulse parameters and obtain strong
more » ... ee OQR without requiring the condition of the sudden-impact limit. To visualize the involved quantum mechanism, we derive a three-state model using the Magnus expansion of the time-evolution operator. Interestingly, the THz pulse interaction with the electric-dipole moment can activate direct multiphoton processes, leading to OQR enhancements beyond that induced by a rotational ladder-climbing mechanism from the rotational ground state. This work provides an explicit and feasible approach toward quantum control of molecular rotation, which is at the core of current research endeavors with potential applications in atomic and molecular physics, photochemistry, and quantum information science.
arXiv:2009.12520v1 fatcat:avmpl6nl7jf2pb3nagsqj7bmuu

Experimental one-step deterministic entanglement purification [article]

Cen-Xiao Huang, Xiao-Min Hu1, Bi-Heng Liu, Lan Zhou, Yu-Bo Sheng, Chuan-Feng Li, Guang-Can Guo
2021 arXiv   pre-print
Entanglement purification is to distill high-quality entangled states from low-quality entangled states. It is a key step in quantum repeaters, determines the efficiency and communication rates of quantum communication protocols, and is hence of central importance in long-distance communications and quantum networks. In this work, we report the first experimental demonstration of deterministic entanglement purification using polarization and spatial mode hyperentanglement. After purification,
more » ... e fidelity of polarization entanglement arises from 0.268±0.002 to 0.989±0.001. Assisted with robust spatial mode entanglement, the total purification efficiency can be estimated as 10^9 times that of the entanglement purification protocols using two copies of entangled states when one uses the spontaneous parametric down-conversion sources. Our work may have the potential to be implemented as a part of full repeater protocols.
arXiv:2110.04970v1 fatcat:osdq3djmy5dazcvyucgrgffkgq

Experimental violation of the local realism for four-qubit Dicke state

Yuan-Yuan Zhao, Yu-Chun Wu, Guo-Yong Xiang, Chuan-Feng Li, Guang-Can Guo
2015 Optics Express  
Dicke state is an widely used type of multi-particle entangled state in quantum information. However, very few works have been done on its nonlocality. Here we prepare a four-photon symmetric Dicke state, whose fidelity is as high as 0.904 ± 0.004, and devise a simple Bell-type inequality to demonstrate that it violates the local realism with 12 standard deviation.
doi:10.1364/oe.23.030491 pmid:26698527 fatcat:qw6ddh2lxfbzphwcgvmxseud24

Spin-photon module for scalable network architecture in quantum dots

Xing-Yu Zhu, Tao Tu, Ao-Lin Guo, Zong-Quan Zhou, Guang-Can Guo, Chuan-Feng Li
2020 Scientific Reports  
Reliable information transmission between spatially separated nodes is fundamental to a network architecture for scalable quantum technology. Spin qubit in semiconductor quantum dots is a promising candidate for quantum information processing. However, there remains a challenge to design a practical path from the existing experiments to scalable quantum processor. Here we propose a module consisting of spin singlet-triplet qubits and single microwave photons. We show a high degree of control
more » ... r interactions between the spin qubit and the quantum light field can be achieved. Furthermore, we propose preparation of a shaped single photons with an efficiency of 98%, and deterministic quantum state transfer and entanglement generation between remote nodes with a high fidelity of 90%. This spin-photon module has met the threshold of particular designed error-correction protocols, thus provides a feasible approach towards scalable quantum network architecture.
doi:10.1038/s41598-020-61976-2 pmid:32193481 fatcat:z4og5zhzrzam7djhaafcypgahi
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