本文是一篇备忘录,主要参考大黄猫老师的《凝聚态物理学导论》,刘川老师的《热力学与统计物理》,David Tong的Statistical Field Theory,符号选取基本与刘川老师的书一致。 证明的基本思路是反证法,假设存在自发对称性破缺,在对称相一侧令序参量趋于零并计算涨落,如果涨落发散则说明不存在自发对称性破缺。 按照刘川老师的...
Mermin-Wagner 定理说：在有限温度下，自旋为 S 的各向同性且交换作用有限长的海森堡模型在一维和二维的...
The absence of ferromagnetism in the 2d-Heisenberg model has been already anticipated by Felix Bloch (Bloch 1930), with physically plausible arguments, based on elementary spin wave theory. In the isotropic Heisenberg ferromagnet at temp... H Wagner,U Schollwoeck - 《Scholarpedia》 被引量: 3发...
quantum theoryBoson systemsGeneral properties structure and representation of Lie groupsQuantum groupsThis is the first of a series of papers considering symmetry properties ofquantum systems over 2D graphs or manifolds, with continuous spins, in thespirit of the Mermin--Wagner theorem. In the model ...
补充资料:Wagner theory of oxidation C.Wagner 分子式: CAS号: 性质:(德)提出的金属高温氧化理论。金属的高温氧化过程受到金属离子和氧离子迁移通过表面氧化膜的速度控制,氧化膜厚度x与氧化时间t之间具有抛物线型关系:x=kt2,其中k称抛物线速度常数,它与氧化物种类、性质、氧化物中的点缺陷含量以及氧分压等因素之间...
The diffraction patterns and the locality of the self-maintaining electromagnetic potential explains also the Quantum Entanglement, giving it as a natural part of the relativistic quantum theory. The asymmetric sides are creating different frequencies of electromagnetic radiations being in the same ...
We observe, from a renormalization group perspective, how the implications of the Mermin-Wagner-Hohenberg theorem set in as we gradually deform theory space towards d = 2. For a fractal dimension in the range 2 < d < 3, we find, for any N 鈮 1, a finite family of multicritical ...
We shall refer to these crystals as being non-σh-symmetric.Since we will be forced to deal with divergences, our use of perturbation theory can only give qualitative hints, but compelling hints nevertheless. Therefore, we will only be able to speculate about possible solutions, intentional or ...
While the proof relies on the (microscopic) Bogoliubov inequality, here we illuminate the theorem from an effective field theory point of view. We estimate the crossover temperature T c and show that, in weak external fields H , it tends to zero: T c ∝ H mathContainer Loading Mathjax (...
翻了下自己的凝聚态场论的书籍。Altland 的 Condensed Matter Field Theory 第415页。Shankar 的 Quantum...