A micro-SQUID with dispersive readout for magnetic scanning microscopy
A micro-SQUID with dispersive readout for magnetic scanning microscopy
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DOI：
10.1063/1.5030489
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发表时间：
2018-06-18
影响因子：
4
通讯作者：
Bluhm, H.
中科院分区：
文献类型：
--
作者：
Foroughi, F.;Mol, J. -M.;Bluhm, H.
我们设计并表征了一种用于低温扫描探针显微镜系统的色散读出的微型鱿鱼。该设计采用电容式分流射频SQUID，谐振频率从5 GHz到12 GHz可调，空间分辨率为微米，集成超导线圈用于局部磁场应用。SQUID作为一个具有依赖于磁通和功率的谐振频率的非线性振荡器来运行。在4K下进行了器件特性和噪声基准的测量。在4K下测得10 kHz以上的磁通噪声为80nPhi(0)HZ(-1/2)，带宽为200 MHz。估算表明，基于约瑟夫森结固有非线性的参数增益可以使磁通噪声在100mK时降低到30nPhi(0)HZ(-1/2)，这相当于位于拾取回路中心的磁矩的10.6mU(B)HZ(-1/2)。由AIP出版公司出版。
We have designed and characterized a micro-SQUID with dispersive readout for use in low temperature scanning probe microscopy systems. The design features a capacitively shunted RF SQUID with a tunable resonance frequency from 5 to 12 GHz, micrometer spatial resolution, and integrated superconducting coils for local application of magnetic fields. The SQUID is operated as a nonlinear oscillator with a flux-and power-dependent resonance frequency. Measurements for device characterization and noise benchmarking were carried out at 4K. The measured flux noise above 10 kHz at 4K is 80 n Phi(0) Hz(-1/2) at a bandwidth of 200MHz. Estimations suggest that one can benefit from parametric gain based on inherent nonlinearity of the Josephson junction and reduce the flux noise to 30 n Phi(0)Hz(-1/2) at 100 mK, which corresponds to 10.6 mu(B)Hz(-1/2) for a magnetic moment located at the center of the pickup loop. Published by AIP Publishing.