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In the realm of modern information technology, data compression technology occupies a pivotal position. With advancements in quantum information technology, the need to compress large-scale qubits ensembles has become urgent, aiming to reduce the demand on quantum storage resources. However, existing quantum state compression schemes generally face a limitation: the particles before and after compression must reside in the same dimensional space. In specific scenarios, compressing qubits into particles of higher dimensions not only enhances the efficiency of quantum state compression but also further reduces the usage of quantum storage resources. Here we experimentally demonstrated a quantum state compression between particles of different dimensions, successfully compressing two qubits into a single qutrit. The average fidelity of the resulting qutrit with the ideal quantum state is 0.8835. Our study may have potential applications in future quantum information, such as increasing quantum communication bandwidth and reducing storage resource consumption in quantum computing. [ABSTRACT FROM AUTHOR]

The Grover quantum search algorithm is a landmark quantum computing application, which has a speed advantage over classical algorithms for searching an unsorted database. For an unsorted database of N items, the classical algorithm needs to search O(N) times, while the Grover algorithm only needs O (N) times. However, except for the special case of N = 4, the traditional Grover algorithm always has some probability of failure. To solve this problem, several schemes for deterministically performing quantum search have been proposed, but they all impose additional requirements on the query Oracle and cannot be implemented in many practical scenarios. Recently, Roy et al. [Phys. Rev. Res. 4, L022013 (2022)] proposed a new deterministic quantum search scheme with no additional requirements on the query Oracle, which has the potential to perfectly replace the traditional Grover algorithm. In this study, we experimentally implement on a programmable silicon quantum photonic chip four deterministic quantum search algorithms, including the Roy algorithm, all of which obtained an average search success rate of over 0.93, exceeding the theoretical maximum of 0.9074 that the traditional Grover algorithm can achieve. Our results demonstrate the feasibility and superiority of the deterministic quantum search algorithms and are expected to facilitate the wider application of these algorithms in future quantum information processing. [ABSTRACT FROM AUTHOR]

This paper analyzes the vertical ground movement during large-scale pipe roof installation and artificial ground freezing of Gongbei tunnel of the Hong Kong-Zhuhai-Macau bridge project. The transverse ground settlement during pipe roof installation is analyzed. The ground loss volume ratio and settlement trough width coefficient during pipe jacking are estimated based on the field measurement of ground settlement. The interaction of pipes during multiple jacking is investigated. The effect of frost heave control by pregrouting, limiting frozen soil thickness, and combination of the two methods is evaluated. The analysis shows that the ground settlement during pipe roof installation by jacking 37 pieces of 1620 mm steel pipes is relatively small with a maximum value of 2.2 cm. The reinforcement to ground provided by the fore-jacked pipes reduces the ground loss volume ratio and, consequently, the ground settlement during the follow-up pipe jacking. The artificial ground freezing generates a relatively large ground heave with a maximum value of 7.8 cm. Pregrouting plays a critical role in the frost heave control by reducing the heave by about 33%. Limiting the frozen soil thickness by heating pipes serves as an effective supplement to frost heave control by reducing the heave by about 9%. The combination of the two measures reduces the ground heave by about 42%. Findings from this paper provide valuable reference to the tunnel construction using pipe roof and artificial ground freezing as presupport. [ABSTRACT FROM AUTHOR]

A novel filamentous actinobacterium, designated strain DHS C013, was isolated from limestone collected in Guizhou Province, South-west China. Morphological and chemotaxonomic characteristics of the strain support its assignment to the genus Lentzea. Phylogenetic analyses showed that strain DHS C013 is closely related to Lentzea jiangxiensis FXJ1.034 (98.7 % 16S rRNA gene similarity) and Lentzea flaviverrucosa 4.0578 (98.0 % 16S rRNA gene similarity), but it can be distinguished from these strains based on low levels of DNA:DNA relatedness (~44 and ~37 %, respectively). Physiological and biochemical tests also allowed phenotypic differentiation of the novel strain from these closely related species. On the basis of the evidence presented here, strain DHS C013 is concluded to represent a novel species of the genus Lentzea, for which the name Lentzea guizhouensis sp. nov. is proposed. The type strain is DHS C013 (=KCTC 29677 = CGMCC 4.7203). [ABSTRACT FROM AUTHOR]

A novel actinomycete, designated strain KLBMP S0043, was isolated from the rhizosphere soil of Artemisia Linn. collected from the coastal region of Lianyungang, Jiangsu Province, in east China and was studied in detail for its taxonomic position. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain KLBMP S0043 is a member of the genus Nocardia. The 16S rRNA gene sequence similarity indicated that strain KLBMP S0043 is closely related to Nocardia asteroides NBRC 15531 (97.61 %) and Nocardia neocaledoniensis SBHR OA6 (97.38 %); similarity to other type strains of the genus Nocardia was found to be less than 97.2 %. The organism has chemical and morphological features consistent with its classification in the genus Nocardia such as meso-diaminopimelic acid as the diagnostic diamino acid in the cell wall peptidoglycan and arabinose and galactose as the diagnostic sugars. The predominant menaquinone was identified as MK-8(Hω-cycl). Mycolic acids were detected. The diagnostic phospholipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. The predominant cellular fatty acids were identified as C, C, Cω9 c, 10-methyl C [tuberculostearic acid (TBSA)] and summed feature 3 (Cω7 c/Cω6 c). The G+C content of the genomic DNA was determined to be 71.4 mol%. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of the strain from its most closely related strains. Based on morphological, chemotaxonomic and phylogenetic data, strain KLBMP S0043 is considered to represent a novel species of the genus Nocardia, for which the name Nocardia rhizosphaerae sp. nov. is proposed. The type strain is KLBMP S0043 (=CGMCC 4.7204 = KCTC 29678). [ABSTRACT FROM AUTHOR]

A quantum algorithm solves computational tasks using fewer physical resources than the best-known classical algorithm. Of most interest are those for which an exponential reduction is achieved. The key example is the phase estimation algorithm, which provides the quantum speedup in Shor's factoring algorithm and quantum simulation algorithms. To date, fully quantum experiments of this type have demonstrated only the read-out stage of quantum algorithms, but not the steps in which input data is read in and processed to calculate the final quantum state. Indeed, knowing the answer beforehand was essential. We present a photonic demonstration of a full quantum algorithm-the iterative phase estimation algorithm (IPEA)-without knowing the answer in advance. This result suggests practical applications of the phase estimation algorithm, including quantum simulations and quantum metrology in the near term, and factoring in the long term. [ABSTRACT FROM AUTHOR]

Quantum computational algorithms exploit quantum mechanics to solve problems exponentially faster than the best classical algorithms. Shor's quantum algorithm for fast number factoring is a key example and the prime motivator in the international effort to realize a quantum computer. However, due to the substantial resource requirement, to date there have been only four small-scale demonstrations. Here, we address this resource demand and demonstrate a scalable version of Shor's algorithm in which the n-qubit control register is replaced by a single qubit that is recycled n times: the total number of qubits is one-third of that required in the standard protocol. Encoding the work register in higher-dimensional states, we implement a two-photon compiled algorithm to factor N = 21. The algorithmic output is distinguishable from noise, in contrast to previous demonstrations. These results point to larger-scale implementations of Shor's algorithm by harnessing scalable resource reductions applicable to all physical architectures. [ABSTRACT FROM AUTHOR]

We present a bulk micromachined in-plane capacitive accelerometer fabricated with an improved process flow, by etching only one-fifth of the wafer thickness at the back of the silicon while forming the bar-structure electrode for the sensing capacitor. The improved flow greatly lowers the footing effect during deep reactive ion etching (DRIE), and increases the proof mass by 54% compared to the traditional way, resulting in both improved device quality and a higher yield rate. Acceleration in the X direction is sensed capacitively by varying the overlapped area of a differential capacitor pair, which eliminates the nonlinear behavior by fixing the parallel-plate gap. The damping coefficient of the sensing motion is low due to the slide-film damping. A large proof mass is made using DRIE, which also ensures that dimensions of the spring beams in the Y and Z directions can be made large to lower cross axis coupling and increase the pull-in voltage. The theoretical Brownian noise floor is 0.47 µg/Hz1/2 at room temperature and atmospheric pressure. The tested frequency response of a prototype complies with the low damping design scheme. Output data for input acceleration from −1 g to 1 g are recorded by a digital multimeter and show very good linearity. The tested random bias of the prototype is 130 µg at an averaging time of around 6 s. [ABSTRACT FROM AUTHOR]

Graph states—multipartite entangled states that can be represented by mathematical graphs—are important resources for quantum computation, quantum error correction, studies of multiparticle entanglement and fundamental tests of non-locality and decoherence. Here, we demonstrate the experimental entanglement of six photons and engineering of multiqubit graph states. We have created two important examples of graph states, a six-photon Greenberger–Horne–Zeilinger state, the largest photonic Schrödinger cat so far, and a six-photon cluster state, a state-of-the-art ‘one-way quantum computer’. With small modifications, our method allows us, in principle, to create various further graph states, and therefore could open the way to experimental tests of, for example, quantum algorithms or loss- and fault-tolerant one-way quantum computation. [ABSTRACT FROM AUTHOR]

The problem of establishing a fair bet between spatially separated gambler and casino can only be solved in the classical regime by relying on a trusted third party. By combining Nash-equilibrium theory with quantum game theory, we show that a secure, remote, two-party game can be played using a quantum gambling machine which has no classical counterpart. Specifically, by modifying the Nash-equilibrium point we can construct games with arbitrary amount of bias, including a game that is demonstrably fair to both parties. We also report a proof-of-principle experimental demonstration using linear optics. Quantum information: Quantum gambling based on Nash-equilibrium Gambling or betting on an event with an uncertain outcome, is one of the most widely practiced activities in human society. Despite its widespread usage and applications, fair gambling between two spatially separated parties cannot be made without the assistance of a trusted third party. A group of international scientists led by Prof. Pei Zhang from Xi'an Jiaotong University, China, has experimentally demonstrated a novel gambling protocol, which enables fair gambling between two distant parties without the help of a third party. By incorporating the key concepts and methods of game theory, their protocol will "force" the two parties to move their strategies to a Nash-equilibrium point which guarantees the fairness through the physical laws of Quantum Mechanics. Furthermore, the authors show that the protocol can be easily adapted to a biased version, which would find applications in lottery, casino, etc. [ABSTRACT FROM AUTHOR]