Buddhiraju Siddharth, Shi Yu, Song Alex, Wojcik Casey, Minkov Momchil, Williamson Ian A D, Dutt Avik, Fan Shanhui
Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA, USA.
Nat Commun. 2020 Feb 3;11(1):674. doi: 10.1038/s41467-020-14504-9.
In the presence of an external magnetic field, the surface plasmon polariton that exists at the metal-dielectric interface is believed to support a unidirectional frequency range near the surface plasmon frequency, where the surface plasmon polariton propagates along one but not the opposite direction. Recent works have pointed to some of the paradoxical consequences of such a unidirectional range, including in particular the violation of the time-bandwidth product constraint that should otherwise apply in general in static systems. Here we show that such a unidirectional frequency range is nonphysical using both a general thermodynamic argument and a detailed calculation based on a nonlocal hydrodynamic Drude model for the metal permittivity. Our calculation reveals that the surface plasmon-polariton at metal-dielectric interfaces remains bidirectional for all frequencies.
在外部磁场存在的情况下，人们认为存在于金属 - 电介质界面的表面等离激元极化激元在表面等离激元频率附近支持一个单向频率范围，在该范围内表面等离激元极化激元沿一个方向传播而不沿相反方向传播。最近的研究指出了这种单向范围的一些矛盾后果，特别是违反了通常在静态系统中应适用的时间 - 带宽积约束。在这里，我们使用一个一般的热力学论证以及基于金属介电常数的非局部流体动力学德鲁德模型的详细计算表明，这样的单向频率范围是不符合物理实际的。我们的计算表明，金属 - 电介质界面处的表面等离激元 - 极化激元在所有频率下都是双向的。
