Nanoscale Gap-Plasmon-Enhanced Superconducting Photon Detectors at Single-Photon Level

With a growing demand for detecting light at the single-photon level in various fields, researchers are focused on optimizing the performance of superconducting single-photon detectors (SSPDs) by using multiple approaches. However, input light coupling for visible light has remained a challenge in the development of efficient SSPDs. To overcome these limitations, we developed a novel system that integrates NbN superconducting microwire photon detectors (SMPDs) with gap-plasmon resonators to improve the photon detection efficiency to 98% while preserving all detector performance features, such as polarization insensitivity. The plasmonic SMPDs exhibit a hot-belt effect that generates a nonlinear photoresponse in the visible range operated at 9 K (similar to 0.64T(c)), resulting in a 233-fold increase in phonon-electron interaction factor (gamma) compared to pristine SMPDs at resonance under CW illumination. These findings open up new opportunities for ultrasensitive single-photon detection in areas like quantum information processing, quantum optics, imaging, and sensing at visible wavelengths.

Automated summary

Researchers have developed a novel system that integrates superconducting wire photon detectors with gap-plasmon resonators, improving the performance of single-photon detectors. The system achieves 98% photon detection efficiency for visible light while preserving polarization insensitivity and other features. These findings open up new opportunities for ultrasensitive single-photon detection in areas like quantum information processing, quantum optics, imaging, and sensing at visible wavelengths.