共查询到20条相似文献,搜索用时 11 毫秒
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The coherent band states of the infinite U lattice Anderson model with introducing a small dispersion into the f-band are derived in the framework of the slave-boson mean field theory. The temperature dependences of the pseudogap in f-band conduction electrons' density of states near the Fermi level are calculated self-consistently. The calculation is applied to discuss the low temperature properties of the heavyelectron metals. The results show that with decreasing temperature the coefficient of the thermoelectric power Q changes sign below the Kondo temperature Tk, and an additional positive peak will appear at the rather lower temperatures, which are in agreement with the experimental results in CeAl3. 相似文献
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Robert Jerrard Alberto Montero Peter Sternberg 《Communications in Mathematical Physics》2004,249(3):549-577
We establish the existence of locally minimizing vortex solutions to the full Ginzburg-Landau energy in three dimensional simply-connected domains with or without the presence of an applied magnetic field. The approach is based upon the theory of weak Jacobians and applies to nonconvex sample geometries for which there exists a configuration of locally shortest line segments with endpoints on the boundary.Research partially supported by NSERC grant number 261955 相似文献
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Francesco Caravelli Gianluca Milano Carlo Ricciardi Zdenka Kuncic 《Annalen der Physik》2023,535(8):2300090
Biological neuronal networks are characterized by nonlinear interactions and complex connectivity. Given the growing impetus to build neuromorphic computers, understanding physical devices that exhibit structures and functionalities similar to biological neural networks is an important step toward this goal. Self-organizing circuits of nanodevices are at the forefront of the research in neuromorphic computing, as their behavior mimics synaptic plasticity features of biological neuronal circuits. However, an effective theory to describe their behavior is lacking. This study provides for the first time an effective mean field theory for the emergent voltage-induced polymorphism of circuits of a nanowire connectome, showing that the behavior of these circuits can be explained by a low-dimensional dynamical equation. The equation can be derived from the microscopic dynamics of a single memristive junction in analytical form. The effective model is tested on experiments of nanowire networks and show that it fits both the potentiation and depression of these synapse-mimicking circuits. It is shown that this theory applies beyond the case of nanowire networks by formulating a general mean-field theory of conductance transitions in self-organizing memristive connectomes. 相似文献
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We study Ising model on Sierpinski carpets by using mean field theory. We find a phase transition at Tc > 0 which is dependent on the geometrical factors. The critical exponents are calculated and found to be the same as the values for translationally invariant lattices. 相似文献
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In this paper we consider a simplified two-dimensional scalar model for the formation of mesoscopic domain patterns in martensitic
shape-memory alloys at the interface between a region occupied by the parent (austenite) phase and a region occupied by the
product (martensite) phase, which can occur in two variants (twins). The model, first proposed by Kohn and Müller (Philos
Mag A 66(5):697–715, 1992), is defined by the following functional:
(E)(u) = 2pb||u(0,·)||2[(H)\dot]1/2([0,h]) + ò0L dx ò0h dy ( |ux|2 + \frace2|uyy| ),\mathcal (E)(u) = 2\pi\beta||u(0,\cdot)||^2_{\dot H^{1/2}([0,h])} + \int_{0}^{L} dx \int_0^h dy\, \big( |u_x|^2 + \frac{\varepsilon}2|u_{yy}| \big), 相似文献
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The single-particle spectrum obtained from the relativistic mean field (RMF) theory is used to extract the shell correction energy with the Strutinsky method. Considering the delicate balance between the plateau condition in the Strutinsky smoothing procedure and the convergence for the total binding energy, the proper space sizes used in solving the RMF equations are investigated in detail by taking ^208 Pb as an example. With the proper space sizes, almost the same shell correction energies are obtained by solving the RMF equations either on basis space or in coordinate space. 相似文献
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在相对论平均场理论框架下,利用粒子数守恒方法处理对关联,给出了具体的理论公式和数值细节;并以24Ne为例,用该方法研究了它的基态和低激发态性质. Particle-number conserving method is adopted to treat the pairing correlations in the relativistic mean-field theory. The formalism and numerical techniques are presented. As an example, the ground state properties and low-lying excited states in~(24)Ne are studied. 相似文献
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The RVB model is investigated by a mean field theory, in which the holon is expressed by a fermion operator, and the spinon by a boson operator. The effective holon-holon interaction by exchanging the spinons is derived for T≠0. It is found that the interaction is attractive. 相似文献
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Konstantin Avrachenkov Arun Kadavankandy Nelly Litvak 《Journal of statistical physics》2018,173(3-4):895-916
We analyse a mean-field model of Personalized PageRank (PPR) on the Erd?s–Rényi (ER) random graph containing a denser planted ER subgraph. We investigate the regimes where the values of PPR concentrate around the mean-field value. We also study the optimization of the damping factor, the only parameter in PPR. Our theoretical results help to understand the applicability of PPR and its limitations for local graph clustering. 相似文献
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研究和详细地比较了RMF理论中不同的有效相互作用强度的密度依赖性, 并且讨论了这种密度依赖性对于核物质和中子星性质的影响. 对于核物质, 不同的参数组给出的对称核物质的饱和点非常接近, 基本都在经验值的范围内. 对于中子星, 考虑超子后不同参数组给出的质量极限的范围为1.52—2.06 M☉, 半径为10.24—11.38 km.The density dependencies of various effective interaction strengths in the relativistic mean field and their influences on the properties of nuclear matter and neutron stars are studied and carefully compared. The differences of saturation properties given by various effective interactions are subtle in symmetric nuclear matter. The Oppenheimer Volkoff mass limits of neutron stars calculated from different equations of state are 1.52—2.06 M☉, and the radii are 10.24—11.38 km with hyperons included. 相似文献
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A new determination of the Lambda-nucleon coupling constants in relativistic mean field theory is presented by optimizing both hyperon binding energy and spin-orbit splitting.Hypernuclear single particle spectra with the new coupling constants suggest the good agreement between the calculation and available data.The spin-orbit splitting of hyperon in medium mass hypernuclei is systematically larger than that in light-or heavy-mass hypernuclei.The sensitivity of the Lambda spin-orbit splitting to the omega-Lambda-Lambda tensor coupling term is also explored. 相似文献
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在相对论平均场理论中引入同位旋标量-矢量介子ω张量项, 以208Pb为例,研究了张量项对原子核平均势场、介子场、自旋-轨道耦合势、单粒子能级的自旋-轨道劈裂和原子核壳层结构等的影响.结果发现张量项对核子平均势的影响主要表现在原子核的表面.随着张量耦合强度的增加, 自旋-轨道耦合势增强,单粒子能级的自旋-轨道劈裂增大,从而导致原子核单粒子能级的壳层结构发生很大变化,传统幻数所对应的主壳消失, 新的主壳出现. 相似文献
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Properties of the ground state of ^178Hf and the isomeric state ^178Hf^m2 are studied within the adiabatic and diabatie constrained relativistic mean field (RMF) approaches. The RMF calculations reproduce well the binding energy and the deformation for the ground state of ^178Hf. Using the ground state single-particle eigenvalues obtained in the present eaiculation, the lowest excitation configuration with K^π = 16^+ is found to be v(7/2^-[514])^-1(9/2^+ [624])^1 π(7/2^+ [404])^-1 (9/2^-[514])^1. Its excitation energy caiculated by the RMF theory with time-odd fields taken into account is equal to 2.801 MeV, i.e., close to the ^178Hf^m2 experimentai excitation energy 2.446 MeV. The self-consistent procedure accounting for the time-odd component of the meson fields is the most important aspect of the present calculation. 相似文献
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