Regensburg 2010 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 31: SC: Tunnelling, Josephson Junctions
TT 31.4: Vortrag
Donnerstag, 25. März 2010, 10:15–10:30, H21
Macroscopic quantum tunneling of Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions modified by current injection — •X. Y. Jin, Y. Koval, Y. Simsek, C. Bergmann, C. Steiner, and P. Müller — Department of Physics and Interdisciplinary Center for Molecular Materials (ICMM), Universität Erlangen-Nürnberg, Germany
The properties of Bi2Sr2CaCu2O8+δ single crystals can be changed in a wide range by current injection along the c-axis. As a result, experiments can be carried out repeatedly on the same sample, only with its critical current density and critical temperature tuned electronically. Macroscopic quantum tunneling experiments were performed on intrinsic Josephson junctions after modification by current injection. A systematic change of the thermal-to-quantum crossover temperature corresponding to the change of critical current density has been observed. Dielectric properties of insulating layers after injection were determined based on microwave spectroscopy experiments. Samples of different structures and geometry have been studied to clarify the current injection mechanism in detail.