Unlocking New Physics and Enabling Plasmonic and Metamaterial Devices with Improved Materials

: Plasmonic and metamaterial devices require high-quality material building blocks with good optical performance, both plasmonic (with the negative real part of the dielectric permittivity) and dielectric, in order to achieve the predicted unusual functionalities and be useful in real world applications. In this project, we have for the first time developed both plasmonic and dielectric materials of the nitrides family that can be grown epitaxially into ultra-thin and ultra-smooth high-quality layers for advanced nanophotonic applications. We have for the first time realized plasmonic waveguides using titanium nitride a gold-like plasmonic ceramic material that has adjustable optical properties, and is robust, low cost and CMOS-compatible. We have showed that a superlattice consisting of titanium nitride as the plasmonic component and aluminum/scandium nitride as the dielectric behaves as an optical hyperbolic metamaterial and exhibits extremely high photonic density-of-states. The outcome of this project is the conclusion that titanium nitride is a very appealing plasmonic material with high performance that could replace and outperform gold in various devices. As a CMOS-compatible material, titanium nitride possesses superior properties compared to noble metals such as adjustable optical properties, high temperature durability, chemical stability, low cost and mechanical hardness that are essential for building nanophotonic devices.