Risk factors of lymph node metastasis in the splenic hilum of gastric cancer patients: a meta-analysis.

Background: The issue of whether or not splenic hilum lymph nodes (SHLN) should be excised in radical gastrectomy with D2 lymph node dissection remains controversial. In this study, we identified the clinicopathological features in patients with gastric cancer that could serve as predictive risk factors of SHLN metastasis.

Methods: We searched Medline, Embase, PubMed, and Web of Science databases from inception to May 2020 and consulted the related references.

Modular quantum computation in a trapped ion system.

Modern computation relies crucially on modular architectures, breaking a complex algorithm into self-contained subroutines. A client can then call upon a remote server to implement parts of the computation independently via an application programming interface (API). Present APIs relay only classical information.

Global entangling gates on arbitrary ion qubits.

Quantum computers can efficiently solve classically intractable problems, such as the factorization of a large number and the simulation of quantum many-body systems. Universal quantum computation can be simplified by decomposing circuits into single- and two-qubit entangling gates, but such decomposition is not necessarily efficient. It has been suggested that polynomial or exponential speedups can be obtained with global N-qubit (N greater than two) entangling gates.

Quantum optical emulation of molecular vibronic spectroscopy using a trapped-ion device.

Molecules are one of the most demanding quantum systems to be simulated by quantum computers due to their complexity and the emergent role of quantum nature. The recent theoretical proposal of Huh (Nature Photon., 9, 615 (2015)) showed that a multi-photon network with a Gaussian input state can simulate a molecular spectroscopic process.

Corrigendum: Experimental Certification of Random Numbers via Quantum Contextuality.

This corrects the article DOI: 10.1038/srep01627.

Experimental quantum simulation of fermion-antifermion scattering via boson exchange in a trapped ion.

Quantum field theories describe a variety of fundamental phenomena in physics. However, their study often involves cumbersome numerical simulations. Quantum simulators, on the other hand, may outperform classical computational capacities due to their potential scalability.

Revealing nonclassicality beyond Gaussian states via a single marginal distribution.

A standard method to obtain information on a quantum state is to measure marginal distributions along many different axes in phase space, which forms a basis of quantum-state tomography. We theoretically propose and experimentally demonstrate a general framework to manifest nonclassicality by observing a single marginal distribution only, which provides a unique insight into nonclassicality and a practical applicability to various quantum systems. Our approach maps the 1D marginal distribution into a factorized 2D distribution by multiplying the measured distribution or the vacuum-state distribution along an orthogonal axis.

Time reversal and charge conjugation in an embedding quantum simulator.

A quantum simulator is an important device that may soon outperform current classical computations. A basic arithmetic operation, the complex conjugate, however, is considered to be impossible to be implemented in such a quantum system due to the linear character of quantum mechanics. Here, we present the experimental quantum simulation of such an unphysical operation beyond the regime of unitary and dissipative evolutions through the embedding of a quantum dynamics in the electronic multilevels of a (171)Yb(+) ion.

Experimental certification of random numbers via quantum contextuality.

The intrinsic unpredictability of measurements in quantum mechanics can be used to produce genuine randomness. Here, we demonstrate a random number generator where the randomness is certified by quantum contextuality in connection with the Kochen-Specker theorem. In particular, we generate random numbers from measurements on a single trapped ion with three internal levels, and certify the generated randomness by showing a bound on the minimum entropy through observation of violation of the Klyachko-Can-Binicioglu-Shumovsky (KCBS) inequality.