論文

査読有り 国際誌
2021年4月9日

Gate-controlled BCS-BEC crossover in a two-dimensional superconductor

Science
  • Yuji Nakagawa
  • ,
  • Yuichi Kasahara
  • ,
  • Takuya Nomoto
  • ,
  • Ryotaro Arita
  • ,
  • Tsutomu Nojima
  • ,
  • Yoshihiro Iwasa

開始ページ
eabb9860
終了ページ
eabb9860
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1126/science.abb9860
出版者・発行元
American Association for the Advancement of Science (AAAS)

Bardeen-Cooper-Schrieffer (BCS) superfluidity and Bose-Einstein condensation (BEC) are the two extreme limits of the ground state of the paired fermion systems. We report crossover behavior from the BCS limit to the BEC limit realized by varying carrier density in a two-dimensional (2D) superconductor, electron-doped layered material ZrNCl. The phase diagram, established by simultaneous measurements of resistivity and tunneling spectra under ionic gating, demonstrates a pseudogap phase in the low doping regime. The ratio of the superconducting transition temperature and Fermi temperature in the low carrier density limit is consistent with the theoretical upper bound expected in the BCS-BEC crossover regime. These results indicate that the gate-doped semiconductor provides an ideal platform for the 2D BCS-BEC crossover without added complexities present in other solid-state systems.

リンク情報
DOI
https://doi.org/10.1126/science.abb9860
URL
https://syndication.highwire.org/content/doi/10.1126/science.abb9860
ID情報
  • DOI : 10.1126/science.abb9860
  • ISSN : 0036-8075
  • eISSN : 1095-9203
  • ORCIDのPut Code : 90837738

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