DC-SQUID串联阵列直流特性研究

Study on the direct current characteristics of DC-SQUID series array

为更好地研究直流超导量子干涉器件(Direct Current Superconducting Quantum Interference Device,DCSQUID)串联阵列的直流特性,我们基于约瑟夫森结RSJ(Resistively Shunted Junction)模型建立了适用于DCSQUID串联阵列的直流关系方程,并通过求解等效福克-普朗克方程,获得了高斯白噪声影响下DC-SQUID串联阵列直流特性的解析表达式。DC-SQUID串联阵列的实测结果验证了本文所提理论公式的正确性。实验结果表明:DC-SQUID串联阵列在低温下具有超高的Fano因子,亟待进一步深入研究。

[Background]The direct current superconducting quantum interference device(DC-SQUID)series array can be used as the second-stage amplifier of two stage DC-SQUID amplifier,or it can be used independently as readout device of Transition Edge Sensor(TES)detectors.[Purpose]This study aims to establish a direct current relationship equation for exploring the DC characteristics of DC-SQUID series array.[Methods]Based on the Josephson junction RSJ(Resistively Shunted Junction)mode,the direct current relationship equation was established.By solving the equivalent Foucault-Planck equation,the analytical expression under the influence of Gaussian white noise was obtained.Data on DC-SQUID series array were collected by high-precision electronics system,and experimental data were used to verify the accuracy of the equation.[Results&Conclusions]The DC circuit model andⅠ-Ⅴrelationship equation are established successfully.The influence of Gaussian white noise on theⅠ-Ⅴcurve is obtained.Experimental results show that the equations and models obtained in this paper are consistent with actual measurement results,and can be used for theoretical research.