Sergey K. Tolpygo1, S. Shokhor1, B. Nadgorny1, J.-Y. Lin1, M. Gurvitch1, A. J. Bourdillon2, S. Y. Hou3, Julia M. Phillips3
1Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794-3800
2Department of Materials Science and Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794-2275
3AT&T Bell Laboratories, Murray Hill, New Jersey, 07974
Tóm tắt
High-Tc Josephson junctions have been fabricated by direct electron beam writing over YBa2Cu3O7 thin-film microbridges, using scanning transmission electron microscope (STEM) with an accelerating voltage of 80–120 kV. Annealing at 330–380 K increases Tc and Ic of the junctions and makes them more stable. In the operating range of a few degrees below Tc, the junctions show 100% magnetic field modulation of the critical current, microwave-induced Shapiro steps oscillating according to the resistively shunted junction (RSJ) model, and RSJ current-voltage characteristics with IcRn product up to 0.5–0.6 mV at 75 K and 0.3 mV at 77 K.
