论文标题
在边界磁场中具有随机不连续性的模型
Ising model in a boundary magnetic field with random discontinuities
论文作者
论文摘要
我们考虑在存在分段恒定边界磁场的空间上的二维ISING场理论，允许沿边界不连续地改变值。我们假设散装中的磁场为零。在退火障碍中，不连续性的位置平均。该模型由边界场理论描述，其中自旋边界条件的叠加被改变边界条件的操作员的集合所扰动。相应的边界耦合给出了磁场的允许恒定值，以及它们之间的过渡的膨化。我们表明，当允许磁场的值仅采用两个不同的值时，这些值在大小上是相同的，但具有不同的符号，模型可以用二次拉格朗日式描述。我们计算和分析此模型的精确反射矩阵。我们还计算边界熵并详细研究三参数空间中RG流的空间，并具有四个不同的红外固定点。我们讨论了扩展模型中可集成性的可能分解，该模型允许通过一些计算来支持边界磁场的两个通用值。
We consider a two-dimensional Ising field theory on a space with boundary in the presence of a piecewise constant boundary magnetic field which is allowed to change value discontinuously along the boundary. We assume zero magnetic field in the bulk. The positions of discontinuities are averaged over as in the annealed disorder. This model is described by a boundary field theory in which a superposition of the free spin boundary condition is perturbed by a collection of boundary condition changing operators. The corresponding boundary couplings give the allowed constant values of the magnetic field as well as the fugacities for the transitions between them. We show that when the value of the magnetic field is allowed to take only two different values which are the same in magnitude but have different signs the model can be described by a quadratic Lagrangian. We calculate and analyse the exact reflection matrix for this model. We also calculate the boundary entropy and study in detail the space of RG flows in a three-parameter space and with four different infrared fixed points. We discuss the likely breakdown of integrability in the extended model which allows for two generic values of the boundary magnetic field, backing it by some calculations.
