Please use this identifier to cite or link to this item: http://localhost/handle/Hannan/633892
Title: Dependence of SQUID Intrinsic Flux Noise on Stewart&x2013;McCumber Parameter beta_{c} of Josephson Junction
Authors: Hai Wang;Yongliang Wang;Xiangyan Kong;Guofeng Zhang;Yi Zhang;Xiaoming Xie
subject: intrinsic flux noise|readout electronics|two-stage scheme (TSS)|Stewart–McCumber parameter beta_{c}$|DC superconducting quantum interference device (SQUID)
Year: 2016
Publisher: IEEE
Abstract: It is known that three superconducting quantum interference device (SQUID) parameters, namely, the intrinsic flux noise &#x03B4;&#x03A6;<sub>s</sub>, the flux-to-voltage transfer coefficient &#x2202;V/&#x2202;&#x03A6;, and the dynamic resistance R<sub>d</sub>, increase with increasing the Stewart- McCumber parameter &#x03B2;<sub>c</sub> of Josephson junction. It is very difficult to obtain the low values of &#x03B4;&#x03A6;<sub>s</sub> for a strongly damped SQUID due to its small &#x2202;V/&#x2202;&#x03A6;. In this paper, we employ a two-stage scheme (TSS) to measure &#x03B4;&#x03A6;<sub>s</sub> directly. Here, we use single chip readout electronics and a weakly damped SQUID with a &#x03B2;<sub>c</sub> of flux noise of the readout-SQUID system is about 4.8 &#x03BC;&#x03A6;<sub>0</sub>/&#x221A;Hz 1.2, both acting as a readout-SQUID system (a preamplifier). The with a corner frequency of about 10 Hz. The front-end SQUID is coupled to the readout SQUID via the input coil with a mutual inductance of M<sub>i</sub>. In our experiment, the flux gain for a readout SQUID, i.e., G<sub>&#x03A6;</sub> = M<sub>i</sub> &#x00D7; (&#x2202;I/&#x2202;&#x03A6;)<sub>front-end</sub> is adjusted to be 20. Using the TSS, we measured &#x03B4;&#x03A6;<sub>s</sub> with different &#x03B2;<sub>c</sub> changing from 0.3 to 13.5 and found &#x03B4;&#x03A6;<sub>s</sub> increasing from 1.0 to 5.0 &#x03BC;&#x03A6;<sub>0</sub>/&#x221A;Hz. We also discussed the relations between L<sub>s</sub>, &#x03B2;<sub>c</sub>, and &#x03B4;&#x03A6;<sub>s</sub> quantitatively. Finally, we proposed designing a suitable &#x03B2;<sub>c</sub> to match the preamplifier in a direct readout scheme to simplify a SQUID measurement system.
URI: http://localhost/handle/Hannan/166895
http://localhost/handle/Hannan/633892
ISSN: 1051-8223
1558-2515
volume: 26
issue: 5
Appears in Collections:2016

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Title: Dependence of SQUID Intrinsic Flux Noise on Stewart&x2013;McCumber Parameter beta_{c} of Josephson Junction
Authors: Hai Wang;Yongliang Wang;Xiangyan Kong;Guofeng Zhang;Yi Zhang;Xiaoming Xie
subject: intrinsic flux noise|readout electronics|two-stage scheme (TSS)|Stewart–McCumber parameter beta_{c}$|DC superconducting quantum interference device (SQUID)
Year: 2016
Publisher: IEEE
Abstract: It is known that three superconducting quantum interference device (SQUID) parameters, namely, the intrinsic flux noise &#x03B4;&#x03A6;<sub>s</sub>, the flux-to-voltage transfer coefficient &#x2202;V/&#x2202;&#x03A6;, and the dynamic resistance R<sub>d</sub>, increase with increasing the Stewart- McCumber parameter &#x03B2;<sub>c</sub> of Josephson junction. It is very difficult to obtain the low values of &#x03B4;&#x03A6;<sub>s</sub> for a strongly damped SQUID due to its small &#x2202;V/&#x2202;&#x03A6;. In this paper, we employ a two-stage scheme (TSS) to measure &#x03B4;&#x03A6;<sub>s</sub> directly. Here, we use single chip readout electronics and a weakly damped SQUID with a &#x03B2;<sub>c</sub> of flux noise of the readout-SQUID system is about 4.8 &#x03BC;&#x03A6;<sub>0</sub>/&#x221A;Hz 1.2, both acting as a readout-SQUID system (a preamplifier). The with a corner frequency of about 10 Hz. The front-end SQUID is coupled to the readout SQUID via the input coil with a mutual inductance of M<sub>i</sub>. In our experiment, the flux gain for a readout SQUID, i.e., G<sub>&#x03A6;</sub> = M<sub>i</sub> &#x00D7; (&#x2202;I/&#x2202;&#x03A6;)<sub>front-end</sub> is adjusted to be 20. Using the TSS, we measured &#x03B4;&#x03A6;<sub>s</sub> with different &#x03B2;<sub>c</sub> changing from 0.3 to 13.5 and found &#x03B4;&#x03A6;<sub>s</sub> increasing from 1.0 to 5.0 &#x03BC;&#x03A6;<sub>0</sub>/&#x221A;Hz. We also discussed the relations between L<sub>s</sub>, &#x03B2;<sub>c</sub>, and &#x03B4;&#x03A6;<sub>s</sub> quantitatively. Finally, we proposed designing a suitable &#x03B2;<sub>c</sub> to match the preamplifier in a direct readout scheme to simplify a SQUID measurement system.
URI: http://localhost/handle/Hannan/166895
http://localhost/handle/Hannan/633892
ISSN: 1051-8223
1558-2515
volume: 26
issue: 5
Appears in Collections:2016

Files in This Item:
File Description SizeFormat 
7469291.pdf768.76 kBAdobe PDFThumbnail
Preview File
Title: Dependence of SQUID Intrinsic Flux Noise on Stewart&x2013;McCumber Parameter beta_{c} of Josephson Junction
Authors: Hai Wang;Yongliang Wang;Xiangyan Kong;Guofeng Zhang;Yi Zhang;Xiaoming Xie
subject: intrinsic flux noise|readout electronics|two-stage scheme (TSS)|Stewart–McCumber parameter beta_{c}$|DC superconducting quantum interference device (SQUID)
Year: 2016
Publisher: IEEE
Abstract: It is known that three superconducting quantum interference device (SQUID) parameters, namely, the intrinsic flux noise &#x03B4;&#x03A6;<sub>s</sub>, the flux-to-voltage transfer coefficient &#x2202;V/&#x2202;&#x03A6;, and the dynamic resistance R<sub>d</sub>, increase with increasing the Stewart- McCumber parameter &#x03B2;<sub>c</sub> of Josephson junction. It is very difficult to obtain the low values of &#x03B4;&#x03A6;<sub>s</sub> for a strongly damped SQUID due to its small &#x2202;V/&#x2202;&#x03A6;. In this paper, we employ a two-stage scheme (TSS) to measure &#x03B4;&#x03A6;<sub>s</sub> directly. Here, we use single chip readout electronics and a weakly damped SQUID with a &#x03B2;<sub>c</sub> of flux noise of the readout-SQUID system is about 4.8 &#x03BC;&#x03A6;<sub>0</sub>/&#x221A;Hz 1.2, both acting as a readout-SQUID system (a preamplifier). The with a corner frequency of about 10 Hz. The front-end SQUID is coupled to the readout SQUID via the input coil with a mutual inductance of M<sub>i</sub>. In our experiment, the flux gain for a readout SQUID, i.e., G<sub>&#x03A6;</sub> = M<sub>i</sub> &#x00D7; (&#x2202;I/&#x2202;&#x03A6;)<sub>front-end</sub> is adjusted to be 20. Using the TSS, we measured &#x03B4;&#x03A6;<sub>s</sub> with different &#x03B2;<sub>c</sub> changing from 0.3 to 13.5 and found &#x03B4;&#x03A6;<sub>s</sub> increasing from 1.0 to 5.0 &#x03BC;&#x03A6;<sub>0</sub>/&#x221A;Hz. We also discussed the relations between L<sub>s</sub>, &#x03B2;<sub>c</sub>, and &#x03B4;&#x03A6;<sub>s</sub> quantitatively. Finally, we proposed designing a suitable &#x03B2;<sub>c</sub> to match the preamplifier in a direct readout scheme to simplify a SQUID measurement system.
URI: http://localhost/handle/Hannan/166895
http://localhost/handle/Hannan/633892
ISSN: 1051-8223
1558-2515
volume: 26
issue: 5
Appears in Collections:2016

Files in This Item:
File Description SizeFormat 
7469291.pdf768.76 kBAdobe PDFThumbnail
Preview File