Department of Electrical and Computer Engineering, University of Victoria , Victoria, British Columbia V8P 5C2, Canada.
Nano Lett. 2017 Apr 12;17(4):2584-2588. doi: 10.1021/acs.nanolett.7b00360. Epub 2017 Mar 20.
Tunnel resistance can be modulated with bias via the Coulomb blockade effect, which gives a highly nonlinear response current. Here we investigate the optical response of a metal-insulator-nanoparticle-insulator-metal structure and show switching of a plasmonic gap from insulator to conductor via Coulomb blockade. By introducing a sufficiently large charging energy in the tunnelling gap, the Coulomb blockade allows for a conductor (tunneling) to insulator (capacitor) transition. The tunnelling electrons can be delocalized over the nanocapacitor again when a high energy penalty is added with bias. We demonstrate that this has a huge impact on the plasmonic resonance of a 0.51 nm tunneling gap with ∼70% change in normalized optical loss. Because this structure has a tiny capacitance, there is potential to harness the effect for high-speed switching.
隧道电阻可以通过库仑阻塞效应通过偏置进行调制，这给出了高度非线性的响应电流。在这里，我们研究了金属-绝缘体-纳米颗粒-绝缘体-金属结构的光学响应，并通过库仑阻塞显示了等离子体隙从绝缘体到导体的切换。通过在隧道间隙中引入足够大的充电能，库仑阻塞允许导体（隧道）到绝缘体（电容器）的转变。当施加偏置时增加高能量罚分时，隧道电子可以再次在纳米电容器上离域。我们证明，这对具有约 70%归一化光损耗变化的 0.51nm 隧道间隙的等离子体共振有巨大影响。由于该结构具有微小的电容，因此有可能利用该效应实现高速开关。
