Development of Prototype Superconducting Diode Element Using REBCO Films with Assymentric Critical Current
土屋 雄司, 鈴木 啓介, 一野 祐亮, 吉田 隆 （名大）
Abstract:Development of superconducting diodes is expected as a new electric rectifying device used in a cryogenic environment for the application such as superconducting electronics and power devices. However, little has been reported on rectifying properties in high-temperature superconducting REBa2Cu3Oy (RE: rare earth, REBCO) films, so further research is needed. Recently, we reported that BaHfO3 (BHO)-doped SmBCO film showed asymmetric critical current characteristics in an in-plane magnetic field.
In this study, we have developed a prototype of superconducting diode element made of the REBCO films which operates in liquid nitrogen without an external field. A BHO-doped SmBCO film was fabricated on a LaAlO3 substrate using a PLD method and was assembled into a diode element. An in-plane field was applied to the REBCO film using two neodymium permanent magnets in the element. The element was cooled with liquid nitrogen without an external magnetic field, and the output voltage was measured with applying an alternating current. DC sub-millivolt output was observed by averaging the voltage when the amplitude of alternating current exceeded the critical current in a direction. The prototype element of the superconducting diode showed the rectification characteristic without an external field.