AI 中文总结
该研究探究局域费米子自旋的QED散射产生的有效自旋相互作用，推导相关哈密顿量与纠缠特性，构建含N自旋的有效相互作用网络以产生多体纠缠。
AI 中文摘要
我们研究局域费米子自旋间量子电动力学（QED）散射产生的有效自旋相互作用。通过积分掉光子与中介场，动力学可简化为有效自旋哈密顿量。对于非相对论区域的两个量子比特，所得相互作用呈张量偶极形式，渐近衰减与\boldsymbol{R}^{-3}成正比。我们得到纠缠负性的解析表达式，强调其对耦合强度与空间构型的依赖关系。随后，我们考察两个浴自旋通过与中间费米中介体的顺序交换发生相互作用的构型，在所考虑的微扰阶下，中介体保持未纠缠状态，并诱导出比光子介导情形空间抑制更强的浴-浴有效相互作用。将该结构扩展至N自旋设置，可得到由虚交换过程介导的有效相互作用网络，该网络能支持系统内多体纠缠的产生。
英文摘要
We study effective spin interactions arising from quantum electrodynamics (QED) scattering between localized fermionic spins. By integrating out photon and mediator fields, the dynamics reduce to an effective spin Hamiltonian. For two qubits in the nonrelativistic regime, the resulting interaction takes a tensor dipolar form with an asymptotic decay proportional to \(R^{-3}\). We obtain analytical expressions for the entanglement negativity, highlighting its dependence on coupling strength and spatial configuration. We then examine a setup in which two bath spins interact via a sequential exchange with an intermediate fermionic mediator. At the perturbative order considered, the mediator remains unentangled and induces an effective bath--bath interaction with stronger spatial suppression than in the photon-mediated case. Extending the construction to an \(N\)-spin setting yields an effective interaction network mediated by virtual exchange processes, which can support the generation of multipartite entanglement across the system.
Comments23 pages, 3 figures
