发表机构
Sorbonne Université, CNRS（索邦大学，法国国家科学研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究利用流体动力学系数、压力平衡表述和单文件对偶性，为一般扩散单文件系统建立了精确非线性响应理论，确定了位移系数和密度分布，并揭示了浴密度偶极矩与力无关的普适规律。
AI 中文摘要
主动微流变通过施加力驱动示踪粒子并测量其响应来探测拥挤介质。在单文件输运中，粒子无法超越彼此，恒力$F$产生亚弹道位移$\langle X_t\rangle\simeq \sqrt{t}\\,\xi(F)$，同时伴随持续的浴介质形变。尽管经过数十年的研究，任意力下的精确非线性响应仍仅限于少数特殊可解模型。在此，我们通过结合流体动力学输运系数的最新进展、局部驱动的压力平衡表述以及单文件对偶性（该对偶性消除了由此产生的移动边界），消除了这一限制。这为一般扩散单文件系统生成了一个闭合的精确边值问题，同时确定了$\xi(F)$和完整的密度分布。对于具有一般相互作用的过阻尼布朗粒子，所有微观相互作用细节仅通过平衡态状态方程进入，从而使现实相互作用系统（包括有限宽准一维通道）能够被精确处理。该解还揭示了普适全局规律；特别是，浴密度偶极矩由施加的力独立于相互作用势而确定。
英文摘要
Active microrheology probes a crowded medium by forcing a tracer and measuring its response. In single-file transport, where particles cannot overtake, a constant force $F$ produces a subballistic displacement $\langle X_t\rangle\simeq \sqrt{t}\,ξ(F)$ together with a persistent bath deformation. Despite decades of work, the exact nonlinear response at arbitrary force has remained confined to a few special solvable models. Here we remove this restriction by combining recent advances in hydrodynamic transport coefficients, a pressure-balance formulation of the local drive, and single-file duality, which eliminates the resulting moving boundary. This yields a closed exact boundary-value problem for general diffusive single files, determining both $ξ(F)$ and the full density profile. For overdamped Brownian particles with general interactions, all microscopic interaction details enter only through the equilibrium equation of state, bringing realistic interacting systems, including finite-width quasi-one-dimensional channels, within exact reach. The solution also reveals universal global laws; in particular, the bath-density dipole is fixed by the applied force independently of the interaction potential.
Comments6 pages + 10 pages of supplemental material
