Comparing the Overhead of Topological and Concatenated Quantum Error Correction

This work compares the overhead of quantum error correction with concatenated and topological quantum error-correcting codes. To perform a numerical analysis, we use the Quantum Resource Estimator Toolbox (QuRE) that we recently developed. We use QuRE to estimate the number of qubits, quantum gates, and amount of time needed to factor a 1024-bit number on several candidate quantum technologies that differ in their clock speed and reliability. We make several interesting observations. First, topological quantum error correction requires fewer resources when physical gate error rates are high, white concatenated codes have smaller overhead for physical gate error rates below approximately 10E-7. Consequently, we show that different error-correcting codes should be chosen for two of the studied physical quantum technologies - ion traps and superconducting qubits. Second, we observe that the composition of the elementary gate types occurring in a typical logical circuit, a fault-tolerant circuit protected by the surface code, and a fault-tolerant circuit protected by a concatenated code all differ. This also suggests that choosing the most appropriate error correction technique depends on the ability of the future technology to perform specific gates efficiently

Christian Literature in Chinese Contexts

Christianity in China has a history dating back to the Tang Dynasty (618–907 CE), when Allopen—the first Nestorian missionary—arrived there in 635. In the late sixteenth century, Matteo Ricci together with other Jesuit missionaries commenced the Catholic missions to China. Protestant Christianity in China began with Robert Morrison, of London Missionary Society, who first set foot in Canton in 1807. Over the centuries, the Western missionaries and Chinese believers were engaged in the enterprise of the translation, publication, and distribution of a large corpus of Christian literature in Chinese. While the extensive distribution of Chinese publications facilitated the propagation of Christianity, the Christian messages have been subtly re-presented, re-appropriated, and transformed by these works of Chinese Christian literature. This Special Issue entitled “Christian Literature in Chinese Contexts” examines the multifarious dimensions of the production, translation, circulation, and reception of Christian literature (with “Christian” and “literature” in their broadest sense) against the cultural and sociopolitical contexts from the Tang period to modern China. The eight articles in this volume cover a variety of intriguing topics, including the literary/translation endeavors of Western missionaries in Chinese, the indigenous works of the Chinese Christians, the interaction between the Christian and Chinese literary traditions, Chinese reception of the Bible, and numerous other relevant concepts

Monotone Branch-and-Bound Search for Restricted Combinatorial Auctions

Faced with an intractable optimization problem, a common approach to computational mechanism design seeks a polynomial time approximation algorithm with an approximation guarantee. Rather than adopt this worst-case viewpoint, we introduce a new paradigm that seeks to obtain good performance on typical instances through a modification to the branch-and-bound search paradigm. Incentive compatibility in single-dimensional domains requires that an outcome improves monotonically for an agent as the agent's reported value increases. We obtain a monotone search algorithm by coupling an explicit sensitivity analysis on the decisions made during search with a correction to the outcome to ensure monotonicity. Extensive computational experiments on single-minded combinatorial auctions show better welfare performance than that available from existing approximation algorithms.Engineering and Applied Science