A high- <i>T</i> <sub>c</sub> van der Waals superconductor based photodetector with ultra-high responsivity and nanosecond relaxation time
Paul Seifert, José Ramón Durán Retamal, Rafael Luque Merino, Hanan Herzig Sheinfux, John N. Moore, Mohammed Ali Aamir, Takashi Taniguchi, Kenji Watanabe, K. Kadowaki, M. Artiglia, M. Romagnoli, Dmitri K. Efetov
Abstract
Abstract Photodetectors based on nano-structured superconducting thin films are currently some of the most sensitive quantum sensors and are key enabling technologies in such broad areas as quantum information, quantum computation and radio-astronomy. However, their broader use is held back by the low operation temperatures which require expensive cryostats. Here, we demonstrate a high- T c superconducting photodetector, which shows orders of magnitude improved performance characteristics of any superconducting detector operated above 77 K, with a responsivity of 9.61 × 10 4 V W −1 , theoretically achievable noise equivalent power of 15.9 fW Hz 1/2 and nanosecond relaxation times. At 15 K the detector reaches an ultra-high performance of 2.33 × 10 7 V W −1 and 55.2 aW Hz 1/2 . It is based on van der Waals heterostructures of the high temperature superconductor Bi 2 Sr 2 CaCu 2 O 8+ δ , which are shaped into nano-wires with ultra-small form factor using focused helium ion beam irradiation. To highlight the versatility of the detector we demonstrate its fabrication and operation on a telecom grade SiN waveguide chip. Our detector significantly relaxes the demands of practical applications of superconducting detectors and displays its possible potential for photonics based quantum applications.