Dai X, Xiang T, Ng T K, Su Z
Physics Department, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Phys Rev Lett. 2000 Oct 2;85(14):3009-12. doi: 10.1103/PhysRevLett.85.3009.
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 omega(J) = 2eV when omega(J) is smaller than the pairing gap but larger than the pairing scattering rate. In the presence of an ac voltage, the tunneling 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 the pair decay rate can be estimated from the half width of the peaks.
我们研究了具有强配对相位涨落的金属与超导体之间隧道结的电流噪声谱。结果表明，当本征约瑟夫森频率ω(J)=2eV小于配对能隙但大于配对散射率时，噪声谱中存在一个特征峰。在存在交流电压的情况下，隧穿电流噪声随直流电压增加呈现出一系列特征峰。对这些峰的实验观测将为高温超导体正常态下的配对涨落提供直接证据，并且配对衰减率可由峰的半高宽来估计。
