Papers by Keyword: Order Parameter

Abstract: The concentration phase transition (CPT) in a two-dimensional ferromagnet was simulated by the Monte Carlo method. The description of the CPT was carried out using various order parameters (OP): magnetic, cluster, and percolation. For comparison with the problem of the geometric (percolation) phase transition, the thermal effect on the spin state was excluded, and thus, CPT was reduced to percolation transition. For each OP, the values ​​of the critical concentration and critical indices of the CPT are calculated.

Abstract: A Numerical calculation of the Fermi Surface (FS) evolution in cuprate using the one-band Hubbard model by the matrix diagonalization method has been done. This work focusses on the study of the evolution of the FS in the cuprate material, namely , numerically by introducing a specific order parameter in the Hubbard model matrix. In this study, we confirm two evolution types of the FS of as an experimental result. Firstly, the evolution of the antibonding FS topology from the electron-like to the hole-like is generated by the order parameter that has a form of where is the order parameter coefficient that corresponds to the hopping parameter of the atomic neighbor long-range interaction and is the normalized momenta coordinate of the first Brillouin zone. On the contrary, the order parameter that has a form of generates the evolution of the FS from the hole-like topology to the electron-like topology. Secondly, the anisotropic evolution of the FS can be described by an extended d-wave order parameter which generating either the V-shape or U-shape type of the energy gap.

Abstract: The approach to determination of the order parameter in the finite 1D Ising model was proposed. For such systems a root mean square magnetization and an average size of the maximal ground state cluster which is formed by neighboring spins with an energy {-2J} does not disappear at T!=0. The temperature dependence of heat capacity and its derivative with respect to temperature from the average size of the maximum quasi ground state cluster, formed by the neighboring spins with an energy {-2J,0} in the 1D Ising chain were considered. The percolation approach in Curie-Weiss does not work due the internal structure of the model.

Abstract: In the discrete 2D XY model of finite number of point dipoles of square spin ice, the order parameter has been calculated exactly as the average size of the maximal cluster. The finite size and edge effects do not allow research the critical behavior of the phase transition for finite systems. It is found that frustrations in spin ice model with long-range interaction are possible only in presence of symmetry for the distribution of magnetic moments.

Abstract: We consider the generalization of the scalar chiral model of graphene, the 8-spinor field being included for the description of spin and quasi-spin excitations. The invariant Lagrangian density quadratic in derivatives is constructed using the principle of energy positivity and that of correspondence with the scalar model. The electromagnetic interaction is included through the extension of derivatives, the Pauli direct interaction term being added. We consider in detail an example of interaction with the external uniform static magnetic field.

Abstract: The modularity logistics system is a new concept produced in network era of globalization. The modularity logistics systems have self-organization characteristic. Combining modularity theory with synergetics theory, the association between modularity logistics systems and logistics standardization system was analyzed. And from the self-organization’s point of view, analyzing the internal and external factors of modularity logistics systems, it was identified that the standardization degree and the modularity value of logistics systems are the order parameters among the co-evolutionary of modularity logistics systems. Finally, introducing synergetics to management science, the collaborative management model of modularity logistics systems is put forward based on the public information supporting platform.

Abstract: The main purpose of designing an evaluation method for routing strategy is to accurately evaluate the performance of a series of routing strategies at various network loads, including under-load, full- load and even overload. Most researchers evaluate the effectiveness of a new routing strategy with the method of Order Parameter. However in this evaluating process, we find that its result distributes in a certain range of values instead of a single value, so Order Parameter introduces a considerable error, it is difficult to evaluate the performance of a routing strategy accurately in different network load with it. To solve this problem, a method--Improved Order Parameter (OOP) is proposed. This method can not only get a fixed critical value for a special network load, but also depict the transition of network load over time. According to simulation experiment, the OOP can be more objective to evaluate the performance of a routing strategy at various network load.

Abstract: Diffraction intensities of a single crystal of Fe₃Pt alloy have been measured by using white X-rays of synchrotron radiation. The observed intensities have been compared with the calculated ones for fundamental and superlattice reflections. By normalizing the calculated intensities of fundamental reflections to the observed ones and evaluating the ratio of the observed intensity of superlattice reflection to the calculated ones, we have estimated the order parameter as 0.82±0.03. The obtained order parameter has been applied to an analysis of the X-ray magnetic diffraction data to estimate the spin moment of Fe and Pt atoms in this alloy.

Abstract: The operational efficiency of power market is infected by the primary conditions of the market, the regulations of government, the balance of need and supply, the behaviors of participants etc. Owing to the characteristics of dynamic complexity, the evaluation for the operational efficiency of the market should develop a new way rather than the traditional way. Based on the synergetic theory, this paper established a synergetic evolution state equation model of the operational efficiency of power market combining with grey cognate principle. According to the data of the Southern power market of China, the order parameter was conformed and the order parameter evolution equation which reflects the operational situation of the market was constructed. Through this equation, the boundary value of the order parameter which implies the market is in effective was given.

Abstract: This paper, on the side of the sustainable development, made a further study of the competitive relationships among the subsystems of resource, environment, economy, and society in the complex system of coalmine construction project to find out how the system develops feasibly first by getting the order parameter in the system, then by measuring the order parameter via the sustainable development level and finally by probing the systematic trend of the coalmine construction project among the various competitive relationships of all subsystems under the theory of system dynamics, from the above of which this paper offers some help and guide in constructing and perfecting the value of the sustainable system of CCP.