"Single electron effects and Bloch oscillations in high-TC superconduct" by G. A. Alvarez and M. Z. Wu

Faculty of Engineering - Papers

Title

Single electron effects and Bloch oscillations in high-TC superconductive tunneling junctions

Authors

G. A. Alvarez, University of Wollongong
M. Z. Wu, Colorado State University

Document Type

Journal Article

Publication Details

This article was originally published as Alvarez, GA, Wang, XL and Dou, SX, Single electron effects and Bloch oscillations in high-TC superconductive tunneling junctions, Journal of Applied Physics, 101(9), 2007, 09G114-1-09G114-3. Copyright American Institute of Physics 2007. Original journal article available here

Abstract

We investigated the effects of single electron charging energy in high-TC superconductors. Various phenomena originated from Coulomb blockade were observable in c-axis NdBa₂Cu₃O₇ −_δ/PrBa₂Cu₃O₇−_δ /NdBa₂Cu₃O₇−_δ superconducting tunnel junctions. The current-voltage characteristics show a Coulomb gap for Cooper pair tunneling when the charging energy exceeds the Josephson coupling energy. A crossover from Coulomb blockade of Cooper pair tunneling to a supercurrent is observed when the ratio of Josephson coupling energy to charging energy is increased. We found a regime in which aspects of the Coulomb blockade of tunneling coexist with features typical of Josephson tunneling. Under microwave irradiation of frequency f, the dynamic resistance dV/ dI as a function of the current I showed sharp singularities at I=2nef, n= ±1, ±2,.... This behavior appears to be very similar to the one predicted by the semiclassical theory of Bloch oscillations.