Cosmological flux noise and measured noise power spectra in SQUIDs.
Cosmological flux noise and measured noise power spectra in SQUIDs.
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DOI：
10.1038/srep28275
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发表时间：
2016-06-20
影响因子：
4.6
通讯作者：
Beck C
中科院分区：
文献类型：
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作者：
Beck C
对于超导器件中常见的1/f磁通噪声的起源，如SQUID和量子比特的理解仍然是一个主要的未解之谜。在这里，我们讨论了在这些装置中测量的观测到的低频通量噪声的很大一部分最终被宇宙学涨落播种的可能性。我们考虑这样一种理论，即宇宙早期的暴涨或量子引力时期遗留下来的不变形式的原始磁通噪声场本质上影响了SQUID和量子比特中的相位差。如果把普朗克合作测量的原始曲率涨落功率谱作为涨落的来源，由这个场产生的扰动种子可以用定量正确的方式解释在SQUID装置中测量的低频磁通噪声谱的形式和幅度。我们的理论预测与最近对不同实验组的低频磁通噪声测量结果非常一致。到目前为止，磁通噪声主要被认为是电子设备的滋扰，因此可能包含关于非常早期宇宙中涨落光谱的有价值的信息。
The understanding of the origin of 1/f magnetic flux noise commonly observed in superconducting devices such as SQUIDs and qubits is still a major unsolved puzzle. Here we discuss the possibility that a significant part of the observed low-frequency flux noise measured in these devices is ultimately seeded by cosmological fluctuations. We consider a theory where a primordial flux noise field left over in unchanged form from an early inflationary or quantum gravity epoch of the universe intrinsically influences the phase difference in SQUIDs and qubits. The perturbation seeds generated by this field can explain in a quantitatively correct way the form and amplitude of measured low-frequency flux noise spectra in SQUID devices if one takes as a source of fluctuations the primordial power spectrum of curvature fluctuations as measured by the Planck collaboration. Our theoretical predictions are in excellent agreement with recent low-frequency flux noise measurements of various experimental groups. Magnetic flux noise, so far mainly considered as a nuisance for electronic devices, may thus contain valuable information about fluctuation spectra in the very early universe.