Nonreciprocity and one-way propagation of optical signals are crucial for modern nanophotonic technology, and typically achieved using magneto-optical effects requiring large magnetic biases. Here we suggest a fundamentally novel approach to achieve unidirectional propagation of surface plasmon-polaritons (SPPs) at metal-dielectric interfaces. We employ a direct electric current in metals, which produces a Doppler frequency shift of SPPs due to the uniform drift of electrons. This tilts the SPP dispersion, enabling one-way propagation, as well as zero and negative group velocities. The results are demonstrated for planar interfaces and cylindrical nanowire waveguides.

中文翻译：

---

电流诱导的表面等离激元-极化子的单向传播

光信号的不可逆性和单向传播对于现代纳米光子技术至关重要，通常使用需要大磁偏置的磁光效应来实现。在这里，我们提出了一种从根本上新颖的方法来实现金属-电介质界面处的表面等离激元-极化子（SPP）的单向传播。我们在金属中使用直流电，由于电子的均匀漂移，该电流会产生SPP的多普勒频移。这会使SPP色散倾斜，从而实现单向传播以及零和负的组速度。结果证明了平面界面和圆柱纳米线波导。