Statistics-dependent quantum co-walking of two particles in one-dimensional lattices with nearest-neighbor interactions

We investigate continuous-time quantum walks of two indistinguishable particles [bosons, fermions or hard-core bosons (HCBs)] in one-dimensional lattices with nearest-neighbor interactions. The results for two HCBs are well consistent with the recent experimental observation of two-magnon dynamics [Nature 502, 76 (2013)]. The two interacting particles can undergo independent- and/or co-walking depending on both quantum statistics and interaction strength. Two strongly interacting particles may form a bound state and then co-walk like a single composite particle with statistics-dependent walk speed. Analytical solutions for the scattering and bound states, which appear in the two-particle quantum walks, are obtained by solving the eigenvalue problem in the two-particle Hilbert space. In the context of degenerate perturbation theory, an effective single-particle model for the quantum co-walking is analytically derived and the walk seep of bosons is found to be exactly three times of the ones of fermions/HCBs. Our result paves the way for experimentally exploring quantum statistics via two-particle quantum walks.Comment: 9 pages, 5 figures, an extension with more new results for our unpublished arXiv:1402.334

Interconnecting bilayer networks

A typical complex system should be described by a supernetwork or a network of networks, in which the networks are coupled to some other networks. As the first step to understanding the complex systems on such more systematic level, scientists studied interdependent multilayer networks. In this letter, we introduce a new kind of interdependent multilayer networks, i.e., interconnecting networks, for which the component networks are coupled each other by sharing some common nodes. Based on the empirical investigations, we revealed a common feature of such interconnecting networks, namely, the networks with smaller averaged topological differences of the interconnecting nodes tend to share more nodes. A very simple node sharing mechanism is proposed to analytically explain the observed feature of the interconnecting networks.Comment: 9 page

Research on the Improvement of Calculation Method for the Interference Assembly of Locomotive Traction Gear

The interference assembly is the main method for the connection between the traction gear and the shaft. The selection of the interference plays a critical role in the design of the traction gear. The traditional method of the calculation of the interference of the traction gear oversimply the mathematical model. The error goes out of the acceptable range so that the old method is not suitable for the design of the web structure. In this paper we propose an improved algorithm for solving the interference of the traction gear by combining the classical elastic mechanics theory and the finite element segmentation technique. The results from our improved algorithm is compared with that from the traditional method and the finite element simulation data is compared with the experimental results. Both comparisons verified the rationality and the feasibility of our algorithm. Our research provides the theoretical reference significance and practical guiding value for the selection of the range of interference