The Greenberger-Horne-Zeilinger (GHZ) states play a significant role in fundamental tests of quantum mechanics and are one of the central resources of quantum-enhanced high-precision metrology, fault-tolerant quantum computing and distributed quantum networks. However, in a noisy environment, entanglement becomes fragile as the particle number increases. Recently, a concatenated GHZ (C-GHZ) state, which retains the advantages of conventional GHZ states but is more robust in a noisy environment, was proposed. Here, we experimentally prepare a three-logical-qubit C-GHZ state. By characterizing the dynamics of entanglement quality of the C-GHZ state under simple collective noise, we demonstrate that the C-GHZ state is more robust than the conventional GHZ state. Our work provides an essential tool for quantum-enhanced measurement and enables a new route to prepare and manipulate macroscopic entanglement. Our result is also useful for linear-optical quantum computation schemes whose building blocks are GHZ-type states.

He Lu;Luo Kan Chen;Chang Liu;平 徐;Xing Can Yao;Li Li;Nai Le Liu;博 赵;宇翱 陈;建伟 潘

Nature Photonics

2014-5

Quantum repeaters hold promise for scalable long-distance quantum communication. The basic building block is a quantum light-matter interface that generates non-classical correlations between light and a quantum memory. Significant progress has been made in improving the performance of this interface, but further development of quantum repeater is hindered by the difficulty of integrating the key capabilities into a single system. Here we report a high-performance interface with an efficiency and lifetime that fulfil the requirement of a quantum repeater. By confining cold atoms with a three-dimensional optical lattice and enhancing the atom-photon coupling with a ring cavity, we observe an initial retrieval efficiency of 76 ± 5% together with a 1/e lifetime of 0.22 ± 0.01s, which supports a sub-Hz entanglement distribution of up to 1,000km through the Duan-Lukin-Cirac-Zoller (DLCZ) protocol. Together with an efficient telecom interface and moderate multiplexing, our result may enable a quantum repeater system that beats direct transmission in the near future.

Sheng Jun Yang;Xu Jie Wang;Xiao Hui Bao;建伟 潘

Nature Photonics

2016-6-1

We present several experimental progresses for advanced quantum communication based on multi-photon entanglement. Quantum secret sharing (QSS) and third-man quantum cryptograph (TQC) shows the advancement in multi-party quantum communication. Quantum error rejection (QER) holds the promise for error-free transfer in long-distance quantum communication. Fault-tolerant quantum cryptography in a decoherence-free subspace (DFS) and quantum-relay-assisted key distribution respectively overcome the difficulties caused by decoherence and photon loss, the two main crucial problems in long-distance quantum communication.

建伟 潘;宇翱 陈;Qiang Zhang

2006

In vivo and in vitro experiments showed that border cell (BC) survival was dependent on root tip mucigel in barley (Hordeum vulgare L. cv. Hang 981). In aeroponic culture, BC development was an induced process in barley, whereas in hydroponic culture, it was a kinetic equilibrium process during which 300-400 BCs were released into water daily. The response of root elongation to temperatures (10-35°C) was very sensitive but temperature changes had no great effect on barley BC development. At 35°C, the root elongation ceased whereas BC production still continued, indicating that the two processes might be regulated independently under high temperature (35°C) stress. Fifty μM Al could inhibit significantly BC development by inhibiting pectin methylesterase activity in the root cap of cv. 2000-2 (Al-sensitive) and cv. Humai 16 (Al-tolerant), but 20 μM Al could not block BC development in cv. Humai 16. BCs and their mucigel of barley had a limited role in the protection of Al-induced inhibition of root elongation, but played a significant role in the prevention of Al from diffusing into the meristems of the root tip and the root cap. Together, these results suggested that BC development was a temperature-insensitive but Al-sensitive process, and that BCs and their mucigel played an important role in the protection of root tip and root cap meristems from Al toxicity.

建伟 潘;Dan Ye;Li Ling Wang;Jing Hua;Gu Feng Zhao;Wei Huai Pan;Ning Han;睦元 朱

Plant and Cell Physiology

2004-6

We report the generation of independent entangled photon pairs from two synchronized but mutually incoherent laser sources. The quality of synchronization is confirmed by observing a violation of Bell's inequality with 3.2 standard deviations in an entanglement swapping experiment. The techniques developed in our experiment are not only important for realistic linear optical quantum-information processing, but also enable new tests of local realism.

Tao Yang;Qiang Zhang;Teng Yun Chen;Shan Lu;Juan Yin;建伟 潘;Zhi Yi Wei;金荣 田;杰 张

Physical Review Letters

2006

Objective: To investigate the relationship between the expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF) and angiogenesis in primary astrocytoma. Methods: Thirty-seven primary astrocytomas and 4 astrocytic hyperplasia samples were collected and divided into three groups according to histological grade. The expression of eNOS, VEGF and factor VIII related antigen (FVIIIRAg) were assayed by immunohistochemistry. Microvascular density was assessed by FVIIIRAg immunoreactivity. The intensity of immunoreactivity was graded according to the percentage of positive tumor cells. Results: No eNOS and VEGF were expressed in the astrocytes and vascular endothelium in astrocytic hyperplasia. The expression of eNOS or VEGF was light in low-grade astrocytoma and strong in glioblastoma. eNOS expression in astrocytoma was very positively correlated with VEGF. eNOS and VEGF expression in anaplastic astrocytoma was median in contrast to the low grade astrocytoma and glioblastoma. Lower microvascular density was found in low grade astrocytoma than that in higher grade malignant ones. The expressions of eNOS and VEGF were correlated with microvascular density and tumor malignancy. Conclusion: This finding suggests that eNOS and VEGF may have cooperative effect in tumor angiogenesis and play an important role in the pathogenesis of primary astrocytoma.

建伟 潘;Ren Ya Zhan;Ying Tong;Yong Qing Zhou;Ming Zhang

Journal of Zhejinag University: Science

2005-7

Some important peptides of bacterial or fungal origin are synthesized via a template-directed, nucleic-acid-independent nonribosomal mechanism. Recent studies revealed that there is a special kind of macroenzymes, nonribosomal peptide synthetases, which plays a key role in the alternative system. Nonribosomal peptide synthetases are composed of modules, the sequences of which contain the message for peptide synthesis. The understanding of the structure and function of nonribosomal peptide synthetases enables scientists believe that some new peptides can be produced by modifying or recombining these special enzymes.

Zhen Huan Ming;建伟 潘;睦元 朱

Progress in Biochemistry and Biophysics

2002-10

The implementation and engineering of bright and coherent solid state quantum light sources is key for the realization of both on chip and remote quantum networks. Despite tremendous efforts for more than 15 years, the combination of these two key prerequisites in a single, potentially scalable device is a major challenge. Here, we report on the observation of bright single photon emission generated via pulsed, resonance fluorescence conditions from a single quantum dot (QD) deterministically centered in a micropillar cavity device via cryogenic optical lithography. The brightness of the QD fluorescence is greatly enhanced on resonance with the fundamental mode of the pillar, leading to an overall device efficiency of η = (74 ± 4) % for a single photon emission as pure as g⁽²⁾(0) = 0.0092 ± 0.0004. The combination of large Purcell enhancement and resonant pumping conditions allows us to observe a two-photon wave packet overlap up to ν = (88±3) %.

Sebastian Unsleber;Yu Ming He;Stefan Gerhardt;Sebastian Maier;Chao Yang Lu;建伟 潘;Niels Gregersen;Martin Kamp;Christian Schneider;Sven Höfling

Optics Express

2016-4-18

Qiang Zhang;Xiang Bin Wang;宇翱 陈;Won Young Hwang;Tao Yang;建伟 潘

Physical Review Letters

2006

A general mapping between CV and discrete systems of arbitrary dimension was established. This allowed construction of all quantum information protocols known for discrete systems also to CV systems.

Caslav Brukner;Myungshik S. Kim;建伟 潘;Anton Zeilinger

Physical Review A - Atomic, Molecular, and Optical Physics

2003-12