Experimental and theoretical studies of d-dot

Takekazu Ishida, Masaki Fujii, Taiji Abe, Masuo Yamamoto, Shigehito Miki, Shuichi Kawamata, Kazuo Satoh, Tsutomu Yotsuya, Masaru Kato, Masahiko Machida, Tomio Koyama, Takahito Terashima, Shigeki Tsukui, Motoaki Adachi

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


We propose the idea of d-dot, where a d-wave superconducting dot is embedded in s-wave matrix. Spontaneous half vortices should appear in the four corners of the d-dot [M. Kato, M. Ako, M. Machida, T. Koyama, T. Ishida, Physica C 412-414 (2004) 352; M. Ako, M. Kato, M. Machida, T. Koyama, T. Ishida, Physica C 412-414 (2004) 544; M. Fujii, T. Abe, H. Yoshikawa, S. Miki, S. Kawamata, K. Satoh, T. Yotsuya, M. Kato, M. Machida, T. Koyama, T. Terashima, S. Tsukui, M. Adachi, T. Ishida, Physica C 426-431 (2005) 104]. Symmetric geometry and the fourfold symmetry of the d-dot would be suitable as a building block for constructing the novel physical systems. The phase dynamics of a closed 0-π junction, which can be realized in a small dx2 - y2-dot, is mapped on a quantum two-level system when the system size is small enough. Using two-component Ginzburg-Landau equation, we study the physical properties of d-dots systematically. We prepare epitaxial YBa2Cu3O7 (YBCO) films of thickness 100 nm on SrTiO3 substrates using a laser ablation apparatus. The d-dot is fabricated by a photolithography, electron beam lithography EB and an electron cyclotron resonance (ECR) etching, a focused ion beam microscope, and a lift-off technique. Local vortex profile is investigated using a SQUID microscope when d-dot is cooled in zero field.

Original languageEnglish
Pages (from-to)104-110
Number of pages7
JournalPhysica C: Superconductivity and its applications
Issue numberSPEC. ISS.
Publication statusPublished - 2006 May 15
Externally publishedYes


  • Ginzburg-Landau equation
  • Quantum two level system
  • d-dot

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering


Dive into the research topics of 'Experimental and theoretical studies of d-dot'. Together they form a unique fingerprint.

Cite this