发表机构
Consiglio Nazionale delle Ricerche (CNR), SPIN Institute（意大利国家研究委员会（CNR），自旋物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文证明标准Langevin噪声形式体系通过假想真空吸收极限过程，在任意量子散射等所有情形下渐近收敛于修正Langevin噪声形式体系，确立了该极限过程的普适有效性。
AI 中文摘要
标准Langevin噪声形式体系（LNF）是无界有损介质中宏观量子电动力学的成熟方法，因此，将其应用于有限物体时，需要赋予周围真空一种假想的吸收，并使其渐近趋于零。现有对该奇异极限过程的论证主要局限于由真空涨落和介质诱导相互作用（如Casimir-Polder力、热辐射、量子发射体动力学等）所支配的现象，从而严格排除了涉及外部量子辐射散射的场景。相反，修正Langevin噪声形式体系（MLNF）最近已被确立为适用于任意宏观系统和电磁过程的完整正则量子理论，完全无需极限过程，将入射量子辐射场视为独立自由度，并在无界介质情形下精确约化为LNF。在本工作中，我们证明LNF极限过程具有普适有效性，即它能在所有情形下（包括任意量子散射过程）恢复MLNF的任何物理预言。具体而言，我们引入一个合适的映射，将任意MLNF态和可观测量与LNF中经假想真空吸收增强的对应实体相关联。随后我们严格证明，当假想吸收趋于零时，通过该映射构造的每个LNF矩阵元都精确收敛到其MLNF对应量，从而该极限过程确立了LNF到MLNF的渐近收敛性。
英文摘要
The standard Langevin noise formalism (LNF) is a well-established approach for macroscopic quantum electrodynamics in unbounded lossy media, and accordingly, its application to finite objects requires endowing the surrounding vacuum with a fictitious absorption that is taken to asymptotically vanish. Existing justifications for such a singular limiting procedure have been mainly restricted to phenomena governed by vacuum fluctuations and medium-induced interactions (Casimir-Polder forces, thermal radiation, quantum emitter dynamics, etc.), thereby strictly excluding scenarios that involve the scattering of external quantum radiation. Conversely, the modified Langevin noise formalism (MLNF) has recently been established as the complete canonical quantum theory for arbitrary macroscopic systems and electromagnetic processes, entirely bypassing the need for limiting procedures, treating incident quantum radiation fields as independent degrees of freedom, and exactly reducing to the LNF for unbounded media. In this work, we demonstrate that the LNF limiting procedure is universally valid by showing that it recovers any physical prediction of the MLNF across all regimes, including arbitrary quantum scattering processes. Specifically, we introduce a suitable mapping associating any MLNF state and observable with a corresponding entity within the LNF augmented by fictitious vacuum absorption. We then rigorously prove that, as the fictitious absorption tends to zero, every LNF matrix element constructed via this mapping exactly converges to its MLNF original, so that the limiting procedure establishes the asymptotic convergence of the LNF to the MLNF.
