Probing Superconducting Phase Fluctuations from the Current Noise Spectrum of Pseudogapped Metal-Superconductor Tunnel Junctions

Xi Dai; Tao Xiang; Tai-Kai Ng; Zhao-bin Su

doi:10.1103/PhysRevLett.85.3009

← Back to search

Probing Superconducting Phase Fluctuations from the Current Noise Spectrum of Pseudogapped Metal-Superconductor Tunnel Junctions

Xi Dai, Tao Xiang, Tai-Kai Ng, Zhao-bin Su

DOI 10.1103/PhysRevLett.85.3009 · Physical Review Letters

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

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 ωJ=2eV when ωJ 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- Tc superconductors and the pair decay rate can be estimated from the half width of the peaks.