Viterbi Faculty of Electrical Engineering, Technion
High-Tc Superconducting Nanoscale Devices
Superconductors have enormous potential for applications in various fields due to their unique properties such as zero-resistance and the Meissner effect. In particular, superconductor integrated devices, such as superconducting nanowire single photon detectors (SNSPDs), are important driving forces of the development in experimental quantum optics. Existing SNSPDs based on low-Tc superconducting materials, such as NbN, Nb, NbSi offer very broadband wavelength detection range and very fast response times on the ps scales. However, they require liquid He cooling down to ~5K, preventing practical applications outside scientific labs, due to bulky equipment and very high costs. The possible application of high-Tc superconductors (HTSs) to implement SNSPDs is challenging, but also promising. Especially copper oxide superconductors show a Tc higher than boiling point of liquid nitrogen (77K), paving the way for portable and cheap single-photon detection technology. Nevertheless, the fabrication of high-Tc nanowires remains a challenge – due to the difficulty in obtaining high-quality uniform films due to the complex structure of the materials and their chemical instability. In our research, several different directions were studied for fabrication methods of (YBCO) nanowires for photon detection. We developed a robust YBCO nanowire fabrication method through selective epitaxial growth (SEG) and demonstrated its the electrical and optical properties, showing high photodetection efficiency. We provide a solution for the superconducting degradation problem often encountered in the fabrication of ultra-narrow nanowires, and open a route to single photon detection based on ultrathin high temperature superconductor. * MSc degree under the supervision of Prof. Alex Hayat.
Date: Mon 17 Feb 2020
Start Time: 15:30
End Time: 16:30
1061 | Electrical Eng. Building