Experimental microwave photonic crystals with controllable band gaps
Phys. Rev. Applied 23, 064036 – Published 13 June, 2025
DOI: https://doi.org/10.1103/pkkz-y5lp
Abstract
Room-temperature photonic crystals (PCs) in the optical frequency range have been widely studied and applied, while those in the microwave frequency range have received relatively less attention, as quantum interferences of microwaves is strongly suppressed at room temperature. In this work, we study the quantum scattering of microwave photons by periodically arranged emitters. We experimentally demonstrated two kinds of microwave PCs generated by periodically arranged microwave cavities and Josephson two-level atoms. We investigate how the bandwidth and central frequency of the generated band gap are influenced by the scattering defects, the dissipation of the scatterers, the photon-scatter coupling strengths, and the separated distances between the nearest-neighbor scatterers. In particular, we show that the central frequency of the band gap generated by the current biased Josephson-junction (CBJJ) array can be dynamically controlled by adjusting the biased dc current. The microwave PCs with controllable band gaps demonstrated here can be applied for microwave quantum information processing.
