非厄米系统中的噪声增强型时间边界态
Noise-enhanced temporal boundary states in non-Hermitian systems
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中文总结 AI 辅助
该研究在二维周期驱动非厄米系统中引入两类时间噪声，发现其可增强时间界面处的响应强度，还在机器人超材料网络中实验实现了噪声增强型时间边界态，揭示时间噪声是拓扑器件的建设性要素。
中文摘要 AI 辅助
时间周期调制引入了一个合成自由度以操控拓扑相，该合成维度可触发相变，使边界态定域在时间界面处。噪声被普遍视为拓扑保护的根本威胁，人们普遍认为它会削弱甚至破坏拓扑态。本文将周期重复的时间噪声与完全随机的时间噪声引入二维周期驱动非厄米系统，矛盾的是，在系综平均下，此类时间噪声会使时间界面处的响应强度呈指数增强。平均超算符分析表明，两种噪声下无噪声带结构均得以保留，但噪声会提升增长模的增长率，同时抑制衰减模的衰减率。最终，我们在机器人超材料网络中实验实现了噪声增强型时间边界态。该发现确立时间噪声为一种建设性要素，可使拓扑态明确显现，并赋予拓扑器件极强的鲁棒性。
英文摘要
Time-periodic modulation introduces a synthetic degree of freedom to manipulate topological phases. This synthetic dimension can trigger a phase transition that localizes a boundary state at the temporal interface. Noise is widely deemed a fundamental threat to topological protection, universally anticipated to weaken or even destroy topological states. Here, we introduce periodically repeated temporal noise and fully random temporal noise into a 2D periodically driven non-Hermitian system. Paradoxically, under ensemble averaging, such temporal noise drives an exponential enhancement of the response intensity at the temporal interface. An averaged superoperator analysis shows that the noiseless band structure is preserved under both types of noise. Yet the noise increases the growth rate of growing modes while suppressing the decay rate of decaying ones. Finally, we experimentally realize the noise-enhanced temporal boundary state in a robotic metamaterial network. This finding establishes temporal noise as a constructive ingredient, enabling the unambiguous emergence of topological states and conferring exceptional robustness upon topological devices.
