arXiv:1010.5892 · Applied Physics Letters

π junction transition in InAs self-assembled quantum dot coupled with SQUID

S. Kim, R. Ishiguro, M. Kamio, Y. Doda, E. Watanabe, D. Tsuya, Kenji Shibata, Kazuhiko Hirakawa, H. Takayanagi

Published Feb 7, 2011• 5 citations

Abstract

We report the transport measurements on the InAs self-assembled quantum dots (SAQDs) which have a unique structural zero-dimensionality, coupled to a superconducting quantum interference device (SQUID). Owing to the SQUID geometry, we directly observe a π phase shift in the current phase relation and the negative supercurrent indicating π junction behavior by not only tuning the energy level of SAQD by back-gate but also controlling the coupling between SAQD and electrodes by side-gate. Our results inspire the future quantum information devices which can link optical, spin, and superconducting state.

DOI: 10.1063/1.3552715

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