Accurate Determination of the Josephson Critical Current by Lock-In Measurements

Nanomaterials

卷:11

Taras Golod¹  Olena M. Kapran¹  Razmik A. Hovhannisyan¹  Vladimir M. Krasnov¹ 

[1] Department of Physics, Stockholm University, AlbaNova University Center, SE-10691 Stockholm, Sweden;

关键词: Josephson effect;    superconductivity;    quantum electronics;    nano-devices;   

DOI  :  10.3390/nano11082058

来源: DOAJ

【 摘 要 】

Operation of Josephson electronics usually requires determination of the Josephson critical current $I_c$, which is affected both by fluctuations and measurement noise. Lock-in measurements allow obviation of $1/f$ noise, and therefore, provide a major advantage in terms of noise and accuracy with respect to conventional dc measurements. In this work we show both theoretically and experimentally that the $I_c$ can be accurately extracted using first and third harmonic lock-in measurements of junction resistance. We derived analytical expressions and verified them experimentally on nano-scale Nb–PtNi–Nb and Nb–CuNi–Nb Josephson junctions.

【 授权许可】

Unknown