Charge solitons in layered superconductors

We studied the interlayer tunneling in Bi-2212 stacks with in plane size va riation down to submicron size. For submicron junctions we found experiment al evidence of Coulomb charging effets. The Coulomb blockade leads to the d rop down of the Josephson critical current density and to appearance of per iodic Coulomb staircase structure of current peaks on the IV characteristic s. The period of the structure corresponds to the charge energy of the sing le Cooper pair charge soliton including the total number of the elementary junctions in the stack (similar to 50). We analyzed conditions of the exist ence of charging effects in layered high-T-c materials of Bi-2212 type.