Abstract: The millimeter/submillimeter wavelengths of the sky contain rich cosmological information, including the cosmic microwave background (CMB) and the CO/[CII] molecular transition lines from large-scale structures of the universe. While the CMB is a gift that keeps giving, line intensity mapping using CO/[CII] emissions provides an alternative method to trace the 3D large-scale structure (LSS) of the universe, potentially reaching higher redshift than optical surveys and accessing more independent information than the 2D cosmic microwave background. A promising technology for mm/submm observations is microwave resonators integrated into silicon chips that are critical for building high-sensitivity, high-density integrated sensor arrays.

I will summarize the current resonator technology status, our efforts to optimize the sensors for demonstration experiments such as SPT-3G+ and SPT-SLIM, more about these experiments, and roadmaps for future surveys.