Scaling the photon-detection area of superconducting nanowire single-photon detectors (SNSPDs) has traditionally been achieved by nanowire meandering. However, material inhomogeneities and fabrication-induced defects, such as line-edge roughness, increase with nanowire length, leading to reduced internal photon-detection efficiency and elevated dark-count rates. This trade-off becomes increasingly pronounced as nanowires are scaled to sub-100 nm widths and sub-5 nm thicknesses required for mid- to far-infrared sensitivity. Here, we demonstrate an antenna-coupled SNSPD architecture that enhances the effective photon-detection area without increasing nanowire length. A crossed bowtie antenna integrated with an 80 nm-wide, 3 nm-thick WSi nanowire yields 15.7× increase in effective detection area at 7.4 μm compared to a bare nanowire of identical geometric footprint, while maintaining the same internal detection efficiency and dark-count rate. Antenna coupling improves noise-equivalent power and provides a more scalable route to increasing photon-detection area than conventional meander geometries, offering performance benefits for applications in astronomy, biological imaging, and molecular spectroscopy.
@article{arxiv.2604.18155,
title = {Enhanced Mid-Infrared Single-Photon Detection with Antenna-Coupled Superconducting Nanowires},
author = {Dip Joti Paul and Stewart Koppell and Gregor G. Taylor and Boris Korzh and Sahil R. Patel and Andrew D. Beyer and Emma E. Wollman and Matthew D. Shaw and Phillip D. Keathley and Karl K. Berggren},
journal= {arXiv preprint arXiv:2604.18155},
year = {2026}
}