2002/12/20 by V. I. Kozub, A. V. Lopatin, V. M. Vinokur · 1 citation
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Fermi energy #Hamiltonian (control theory) #Hubbard model #Impurity #Josephson effect #Physics #Physics of Superconductivity and Magnetism #Pi Josephson junction #Quantum and electron transport phenomena #Quantum mechanics #Quantum tunnelling #Sign (mathematics) #Superconductivity #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.90.226805
arxiv created 2002/12/20 · openalex publication_date 2003/06/04 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the Josephson transport through a thin semiconductor barrier containing impurity centers with the on-site Hubbard interaction u of an arbitrary sign and strength. We find that in the case of the repulsive interaction the Josephson current changes sign with the temperature increase if the energy of the impurity level epsilon (measured from the Fermi energy of superconductors) falls in the interval (-u,0). We predict strong temporal fluctuations of the current if only a few centers are present within the junction. In the case of the attractive impurity potential (u<0) and at low temperatures, the model is reduced to the effective two level Hamiltonian allowing thus a simple description of the nonstationary Josephson effect in terms of pair tunneling processes.