已知通过生物和固态纳米通道的离子传输是高噪声过程。根据经验，电流波动的功率谱与频率的倒数一样，遵循长期存在但知之甚少的Hooge定律。在这里，我们报告的纳米尺度的二维通道具有不同的表面特性的电流波动的测量。发现涨落的结构依赖于沟道的材料。虽然在原始通道中，电流波动像$1/f^{1+a}$与$a = 0 - 0.5$一样缩放，但活化石墨通道的噪声功率谱根据频率显示不同的状态。基于这些观察，我们开发了一个理论形式主义直接连接离子动力学和电流波动。我们预测，噪声功率谱的形式为$1/f \times S_\text{channel}(f)$，其中$1/f$波动出现在流体水库两侧的通道和$S_\text{channel}$描述波动inside it. Deviations到Hooge定律，从而允许直接访问的离子输运动力学的通道-解释整个现象在实验中观察到的2D纳米通道。我们的研究结果表明，电流波动可以用来表征纳米离子动力学。
英文摘要：
Ion transport through biological and solid-state nanochannels is known to be a highly noisy process. The power spectrum of current fluctuations is empirically known to scale like the inverse of frequency, following the long-standing yet poorly understood Hooge's law. Here, we report measurements of current fluctuations across nanometer-scale two-dimensional channels with different surface properties. The structure of fluctuations is found to depend on channel's material. While in pristine channels current fluctuations scale like $1/f^{1+a}$ with $a = 0 - 0.5$, the noise power spectrum of activated graphite channels displays different regimes depending on frequency. Based on these observations, we develop a theoretical formalism directly linking ion dynamics and current fluctuations. We predict that the noise power spectrum take the form $1/f \times S_\text{channel}(f)$, where $1/f$ fluctuations emerge in fluidic reservoirs on both sides of the channel and $S_\text{channel}$ describes fluctuations inside it. Deviations to Hooge's law thus allow direct access to the ion transport dynamics of the channel -- explaining the entire phenomenology observed in experiments on 2D nanochannels. Our results demonstrate how current fluctuations can be used to characterize nanoscale ion dynamics.
Effects of Divalent Cations on Diffusion Dynamics of Biological Water Confined between Lipid Membranes
Global Science Research Center for Systems Chemistry (GCSC)（系统化学全球研究中心）；Department of Chemistry, Chung-Ang University（中央大学化学系）；Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS)（基础科学研究院分子光谱与动力学中心）；Department of Chemistry, Korea University（韩国大学化学系）
Dielectric permittivity of water confined in stacks of charged lipid layers: extracting profiles from molecular dynamics simulations using a modified Poisson-Boltzmann equation
Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière（里昂第一大学，法国国家科学研究中心，光物质研究所）；UPR 22/CNRS, Institut Charles Sadron, Université de Strasbourg（斯特拉斯堡大学，法国国家科学研究中心查尔斯·萨德龙研究所）
Surface Charge Doping for Ion-Pairing Criticality in Confined Electrolytes
Southern University of Science and Technology（南方科技大学）；Shenzhen Municipal Key-Lab for Advanced Quantum Materials and Devices, and Guangdong Provincial Key Lab for Computational Science and Materials Design, Southern University of Science and Technology（南方科技大学深圳市先进量子材料与器件重点实验室、广东省计算科学与材料设计重点实验室）
