【摘要】 利用电阻加热、单源混合分层蒸镀方法制备的 Bi PbSrCaCuO 超导薄膜,研制成功带双桥结的单圆孔的直流超导量子干涉器（dc SQUID）.这些 dc SQUID 在78K 呈现出完全的周期性磁通响应的电压特性.在无屏蔽条件下,0—1Hz 频率范围内,78K 的磁通噪声的典型值为1.7×10^-3φ₀/（Hz）^1/2,相应的能量分辨率为3.6×10^-26J/Hz.同时,我们发现了无偏置电流下的可以锁定的磁通响应的电压二次谐波现象,此现象尚未理解清楚,但它与 dc SQUID的 I—V 特性形状有密切关系,并对其进行了探讨.更多还原

【Abstract】 DC-SQUIDs (Superconducting Quantum Interference Devices) have been successfully fabricated by using Pb doped BiSrCaCuO superconducting thin film made by mixed evaporation of single source of resistance heating. The dc SQUID consists of single round-washer with double bridge junctions. These SQUIDs show perfectly periodic voltage-flux characteristics. Under without magnetic shield, the typical flux noise and energy resolution in a frequency range from DC to 1Hz at 78K are 1.7×10-3 φ0/Hz1/2 and 3.6 ×10-26J/Hz, respectively. Meanwhile, we have found out that one of SQUIDs operated on flux-locked mode showing voltage-flux second harmonic under no bias currents in the measuring circuit. This phenomenon is not clearly understood, but it is related to I-V characteristic of the dc-SQUID. We only discuss about it.更多还原