GIANT JOSEPHSON CURRENT THROUGH A SINGLE BOUND-STATE IN A SUPERCONDUCTING TUNNEL JUNCTION

We study the microscopic structure of the Josephson current in a singl e-mode tunnel junction with a wide quasiclassical tunnel barrier. In s uch a junction each Andreev bound state carries a current of magnitude proportional to the amplitude of the normal electron transmission thr ough the junction. Tremendous enhancement of the bound-state current i s caused by the resonance coupling of superconducting bound states at both superconductor-insulator interfaces of the junction. The possibil ity of experimental observation of the single bound-state current is d iscussed.