Center for Subwavelength Optics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
ACS Nano. 2011 Oct 25;5(10):8340-5. doi: 10.1021/nn2031885. Epub 2011 Oct 11.
Nanoscale metallic barriers embedded in terahertz (THz) slot antennas are shown to provide unprecedented control of the transition state arising at the crossover between the full- and half-wavelength resonant modes of such antennas. We demonstrate strong near-field coupling between two paired THz slot antennas separated by a 5 nm wide nanobarrier, almost fully inducing the shift to the resonance of the double-length slot antenna. This increases by a factor of 50 the length-scale needed to observe similar coupling strengths in conventional air-gap antennas (around 0.1 nm), making the transition state readily accessible to experiment. Our measurements are in good agreement with a quantitative theoretical modeling, which also provides a simple physical picture of our observations.
在太赫兹（THz）缝隙天线中嵌入纳米级金属阻挡层，可对这种天线全波长和半波长谐振模式转换时的过渡状态进行前所未有的控制。我们演示了通过一个 5nm 宽纳米阻挡层分离的两个成对 THz 缝隙天线之间的强近场耦合，几乎完全诱导双长度缝隙天线的共振位移。这使得在传统气隙天线（约 0.1nm）中观察到类似耦合强度所需的长度尺度增加了 50 倍，使过渡状态更容易进行实验观察。我们的测量结果与定量理论模型吻合较好，该模型还为我们的观察提供了一个简单的物理图像。
