2024/06/05 by Subhomoy Haldar, Haldar, Subhomoy, Harald Havir +15 · 3 citations
Engineering · #Advanced Photonic Communication Systems #Applied Physics (physics.app-ph) #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Photonic and Optical Devices #Quantum Physics (quant-ph) #Semiconductor Lasers and Optical Devices
paper · pdf · doi:10.48550/arxiv.2406.03047
openalex publication_date 2024/06/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/02
We present a superconducting cavity-coupled double quantum dot (DQD) photodiode that achieves a maximum photon-to-electron conversion efficiency of 25% in the microwave domain. With a higher-quality-factor cavity and improved device design to prevent photon leakages through unwanted pathways, our device measures microwave signals down to 100 aW power level and achieves sensitivity to probe microwave signals with one photon at a time in the cavity. We analyze the photodiode operation using Jaynes-Cummings input-output theory, identifying the key improvements of stronger cavity-DQD coupling needed to achieve near-unity photodetection efficiency. The results presented in this work represent a crucial advancement toward near unity microwave photodetection efficiency with single cavity-photon sensitivity for studies of photon statistics in the microwave range and applications related to quantum information processing.