High Temperature Superconductors for single photon detection – HECTOR

Superconducting Single Photon Detectors (SSPD) are central element for numerous applications including time-of-time imaging and quantum cryptography systems. They consist of superconducting nanowires biased near their critical current. A (visible or near IR) photon absorption creates a hotspot that is converted into a measurable voltage pulse. Low-Tc SSPD have the best performances at 4K but need energy-consuming 4K cryogenics. We propose to fabricate high-Tc SSPD with YBa2Cu3O7 and Bi2Sr2CaCu2O8+x that will operate at higher temperature (40K) with simplified cryogenics and at higher frequency, and to investigate the far-from-being-understood microscopic mechanism leading to hotspot formation. We will perform global transport measurements on a biased YBCO and field effect tunable BiSCCO nanowires. We will explore the phase diagram influence on the development of a hotspot. This will give information about the physics of the systems, and will help improving high Tc SSPDs.