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Probing superconducting phase fluctuations from the current noise spectrum of pseudogaped metal-superconductor tunnel junctions

Xi Dai·Tao Xiang·Tai-Kai Ng·Zhao-bin Su
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Abstract

We study the current noise spectra of a tunnel junction of a metal with strong pairing phase fluctuation and a superconductor. It is shown that there is a characteristic peak in the noise spectrum at the intrinsic Josephson frequency $ω_J=2eV$ when $ω_J$ is smaller than the pairing gap but larger than the pairing scattering rate. In the presence of an AC voltage, the tunnelling current noise shows a series of characteristic peaks with increasing DC voltage. Experimental observation of these peaks will give direct evidence of the pair fluctuation in the normal state of high-$T_c$ superconductors and from the half width of the peaks the pair decay rate can be estimated.

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Xi Dai, Tao Xiang, Tai-Kai Ng, Zhao-bin Su. 2000-03-24. Probing superconducting phase fluctuations from the current noise spectrum of pseudogaped metal-superconductor tunnel junctions. https://doi.org/10.1103/physrevlett.85.3009

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