超伝導と電荷密度波がナノレベルで本質的に結びついていることを発見し、次世代のエレクトロニクスやコンピュータにつながる新しい理解を示した。 Scientists discover superconductivity and charge density waves are intrinsically interconnected at the nanoscopic level, a new understanding that could help lead to the next generation of electronics and computers.
2022-05-20 SLAC国立加速器研究所
The team aimed infrared laser pulses at the YBCO sample to switch off its superconducting state, then used X-ray laser pulses to illuminate the sample and examined the X-ray light scattered from it. Their results revealed that regions of superconductivity and charge density waves were arranged in unexpected ways. (Courtesy Giacomo Coslovich/SLAC National Accelerator Laboratory)
米エネルギー省SLAC国立加速器研究所、ブリティッシュ・コロンビア大学、イェール大学などの研究者が、イットリウムバリウム銅酸化物（YBCO）と呼ばれる物質の高速ダイナミクスを研究し、その方向へ一歩踏み出すことに成功した。
研究チームは、YBCOの超伝導が、電荷密度波（CDW）、すなわち材料中の電子密度の波紋として知られる別の現象と予想外の形で絡み合っていることを、5月20日付の『Science』誌で報告した。研究者たちが予想したとおり、YBCOの超伝導をオフにすると、CDWはより強くなる。これは、超伝導がCDWの形をナノスケールで根本的に変えていることを示唆している。
＜関連情報＞
- https://www6.slac.stanford.edu/news/2022-05-20-superconductivity-and-charge-density-waves-caught-intertwining-nanoscale.aspx
- https://www.science.org/doi/10.1126/science.abd7213
光クエンチした高温超伝導体における電荷密度波コヒーレンスの増強 Enhanced charge density wave coherence in a light-quenched, high-temperature superconductor
S. WANDEL,F. BOSCHINI,E. H. DA SILVA NETO,L. SHEN,M. X. NA,S. ZOHAR,Y. WANG ,S. B. WELCH ,M. H. SEABERG,J. D. KORALEK,G. L. DAKOVSKI,W. HETTELM.-F. LIN ,S. P. MOELLER ,W. F. SCHLOTTER ,A. H. REID ,M. P. MINITTI ,T. BOYLE ,F. HE ,R. SUTARTO,R. LIANGD. BONN,W. HARDY ,R. A. KAINDL ,D. G. HAWTHORN ,J.-S. LEE ,A. F. KEMPER,A. DAMASCELLI,C. GIANNETTI ,J. J. TURNER AND G. COSLOVICH
Science Published:19 May 2022
DOI: 10.1126/science.abd7213
Abstract
Superconductivity and charge density waves (CDWs) are competitive, yet coexisting, orders in cuprate superconductors. To understand their microscopic interdependence, a probe capable of discerning their interaction on its natural length and time scale is necessary. We use ultrafast resonant soft x-ray scattering to track the transient evolution of CDW correlations in YBa2Cu3O6+x after the quench of superconductivity by an infrared laser pulse. We observe a nonthermal response of the CDW order characterized by a near doubling of the correlation length within ≈1 picosecond of the superconducting quench. Our results are consistent with a model in which the interaction between superconductivity and CDWs manifests inhomogeneously through disruption of spatial coherence, with superconductivity playing the dominant role in stabilizing CDW topological defects, such as discommensurations.
