%0 Journal Article %T Two-Path Solid-State Interferometry Using Ultra-Subwavelength 2D Plasmonic Waves %A Kitty Y. M. Yeung %A Hosang Yoon %A William Andress %A Ken West %A Loren Pfeiffer %A Donhee Ham %J Physics %D 2012 %I arXiv %R 10.1063/1.4775668 %X We report an on-chip solid-state Mach-Zehnder interferometer operating on two-dimensional (2D) plasmonic waves at microwave frequencies. Two plasmonic paths are defined with GaAs/AlGaAs 2D electron gas 80 nm below a metallic gate. The gated 2D plasmonic waves achieve a velocity of ~c/300 (c: free-space light speed). Due to this ultra-subwavelength confinement, the resolution of the 2D plasmonic interferometer is two orders of magnitude higher than that of its electromagnetic counterpart at a given frequency. This GHz proof-of-concept at cryogenic temperatures can be scaled to the THz IR range for room temperature operation, while maintaining the benefits of the ultra-subwavelength confinement. %U http://arxiv.org/abs/1212.4170v1