AI 中文总结
研究带隙狄拉克系统中 Breit 型哈密顿量，基于路径积分场论，通过积分掉高能分量得到低能描述，普通方程可重现传统哈密顿量，轴矢场存在时会有新耦合，用狄拉克模型说明方法及与外尔系统的相关性。
AI 中文摘要
我们开发了一种基于路径积分的场论，用于推导与矢量和轴矢规范场耦合的带隙狄拉克系统的 Breit 型低能哈密顿量。将质量间隙视为大能量尺度，我们积分掉狄拉克旋量的高能分量，得到剩余低能自由度的正则薛定谔描述。对于普通狄拉克方程，我们的方法逐阶重现传统 Breit 哈密顿量。然而，在存在轴矢规范场的情况下，所得哈密顿量包含传统电磁情形中没有类似物的额外矢量 - 轴矢耦合。我们用三维和二维狄拉克模型说明了该方法，并讨论了其与带隙外尔系统的相关性，其中动态轴矢场可产生独特的低能输运特征。
英文摘要
We develop a path-integral-based field theory for deriving Breit-type low-energy Hamiltonians for gapped Dirac systems coupled to both vector and axial gauge fields. Treating the mass gap as the large energy scale, we integrate out the high-energy component of the Dirac spinor and obtain a canonical Schrödinger description for the remaining low-energy degrees of freedom. For the ordinary Dirac equation, our method reproduces the conventional Breit Hamiltonian order by order. In the presence of axial gauge fields, however, the resulting Hamiltonian contains additional vector-axial couplings that have no analogue in the traditional electromagnetic case. We illustrate the method using three- and two-dimensional Dirac models and discuss its relevance to gapped Weyl systems, where dynamical axial fields can generate distinctive low-energy transport signatures.
Comments12 pages, 0 figure
