PHYSICAL REVIEW LETTERS, vol.111, no.7, 2013 (SCI-Expanded)
Lumped circuit elements (i.e., resistors, capacitors, and inductors) provide the basic building blocks of microelectronic devices ubiquitous in information processing, storage, and communications. The use of these modular quasistatic components can be extended to the nanoscale optical regime to achieve high-density, high-speed analogues of these traditional circuits. We reimagine these devices in the near-infrared (NIR) regime, making use of a simple nanorod geometry and plasmonic transparent conducting oxides (TCOs). We evaluate their equivalent impedance as lumped circuit elements and construct bandpass and band-stop filters operating at NIR wavelengths. Through variation in the TCO nanorod geometry and the addition of PbS nanocrystals in between and NiCr on top of the TCO nanorods, we present the first designable NIR lumped nanocircuits with tailorable response. The experimental results agree with both circuit models and full-wave simulations.