Superconductor Science and Technology

Single-electron tunnelling devices based on intrinsic Josephson junctions in Bi-2212

Takashi Yamashita, S Kim, Yu. I. Latyshev

Published Jan 1, 2000• 3 citations

Abstract

We fabricated submicron-sized intrinsic Josephson junctions of Bi-2212 by the focused-ion-beam (FIB) etching method. The main result was a reduction of the in-plane junction area to 0.3 µm 2 by direct FIB etching with no degradation in the critical transition temperature ( T c ). At the current ( I )-voltage ( V ) characteristic of these stacks, the gap structure and the normal-state resistance are clearly observed by a reduction of the Joule heating. The critical current density is considerably suppressed, the hysteresis and multibranch structure are eliminated and a periodic structure of current peaks appears reproducibly on the I - V curves. The period V of the structure is consistent with the Coulomb charging energy of a single pair, V = e / C , where C is the effective capacitance of the stack. It is considered that this behaviour originates from the Coulomb blockade of intrinsic Josephson tunnelling in submicron Bi-2212 stacks. We demonstrated the junction operating up to 10 K for the stack with an in-plane size of 0.3 µm 2 and an elementary junction number of 50.

DOI: 10.1088/0953-2048/13/1/314

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