2025/07/01 by Leif Bauer, Daien He, Bauer, Leif +9 · 1 citation
Computer Science · Materials Science · Physics and Astronomy · #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum Information and Cryptography #Superconductivity (cond-mat.supr-con) #Superconductivity in MgB2 and Alloys
paper · pdf · doi:10.48550/arxiv.2507.01240
openalex publication_date 2025/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Photon detectors based on type-2 superconductors have found widespread applications from on-chip quantum computing to quantum remote sensing. Here, we develop the theory for a new class of type-1.5 superconducting nanowire single photon detectors (SNSPDs) based on two bandgap superconductors with high transition temperatures such as MgB2 (Tc ~38.6K). We show that vortex-vortex interactions in two component condensates lead to a unique operating regime where single photons can seed multiple vortices within a hotspot. We also show that dark counts are suppressed in the type-1.5 regime compared to the widely studied type-2 SNSPDs. Our work opens the door for exploring the unique vortex physics of two-gap superconductors for quantum device applications.