Superconducting quantum interference devices (SQUIDs) are currently used as magnetic flux detectors with ultra-high sensitivity for various applications such as medical diagnostics and magnetic material microstructure analysis. Single-crystalline superconducting boron-doped diamond is an excellent candidate for fabricating high-performance SQUIDs because of its robustness and high transition temperature, critical current density, and critical field. Here, we propose a fabrication process for a single-crystalline boron-doped diamond Josephson junction with regrowth-induced step edge structure and demonstrate the first operation of a single-crystalline boron-doped diamond SQUID above 2 K. We demonstrate that the step angle is a significant parameter for forming the Josephson junction and that the step angle can be controlled by adjusting the microwave plasma-enhanced chemical vapour deposition conditions of the regrowth layer. The fabricated junction exhibits superconductor–weak superconductor–superconductor-type behaviour without hysteresis and a high critical current density of 5800 A/cm2.
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机译:当前,超导量子干扰设备(SQUID)被用作具有超高灵敏度的磁通检测器,用于医疗诊断和磁性材料微结构分析等各种应用。单晶超导掺硼金刚石由于其坚固性和高转变温度,临界电流密度和临界场而成为制造高性能SQUID的理想选择。在这里,我们提出了一种具有再生长台阶边缘结构的单晶掺硼金刚石约瑟夫逊结的制造工艺,并演示了单晶掺硼金刚石SQUID在2 K以上的首次工作。是形成约瑟夫森结的重要参数,并且可以通过调节再生层的微波等离子体增强的化学气相沉积条件来控制阶梯角。制成的结表现出超导体-弱超导体-超导体类型的行为,没有磁滞现象,并且具有5800 A / cm 2 sup>的高临界电流密度。
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