Invited Paper IPF-TuA8
Circuits with Light at the Nanoscale

Tuesday, October 16, 2007, 4:00 pm, Room 602/603

For many years, the familiar notion of lumped circuit elements has been extensively and successfully used in microelectronics. This concept has allowed "modularization" of various functions at the circuit level, and thus has been proven to be a powerful tool in design, innovation, and discovery of new functionalities in the radio frequencies (RF) and microwaves. Can the concept of lumped circuit elements, and the mathematical machinery of circuit theory, be extended into the nanometer scale and into the optical domain? In other words, can we envision nanostructures that may act as a "module" representing a lumped circuit element, such as a nanoinductor, a nanocapacitor, a nanoresistor, and a nanodiode, etc. that will work with light, instead of electricity? Utilizing the notion of metamaterials and plasmonic materials with unusual values for material parameters such as negative or near-zero parameters, we have developed the concept of lumped circuit elements at the higher frequency regimes, such as terahertz (THz), infrared (IR), and optical domains. With this approach, nanoelements such as nanoinductors, nanocapacitors, nanoresistors, and nanodiodes can indeed be envisioned at optical frequencies by properly arranging plasmonic and nonplasmonic nanostructures as a tapestry of nanoparticles. This new circuit paradigm, which we coin "meta-nanocircuits" inspired by metaplasmonics, provides us with the possibility of tailoring and manipulating optical electric fields with desired patterns in sub-wavelength regions, and thus allows the mathematical tools of circuit theory to be used in the THz, IR and optical frequencies. This will open doors to many innovations in future optical nanoelectronics and nanosystems, and may likely lead to a new paradigm for information processing, detection, and storage, in the nanometer scales. In our theoretical and computational works, we have shown how more general circuits with various transfer functions can be considered by using blocks of nanostructures, providing new ways of designing nano-scale optical lumped components and devices such as filters, switches, etc. at optical wavelengths. Such meta-nanocircuits may one day be also interfaced with biological circuits, leading to the possibility of hybrid nano-bio circuits. In this talk, I will present an overview of some of our theoretical results and computational simulations on this concept of metactronics - metamaterial electronics.