한국초전도ㆍ저온공학회논문지 (Progress in Superconductivity and Cryogenics)

  • 제28권2호
  • /
  • Pages.8-11
  • /
  • 2026
  • /
  • 1229-3008(pISSN)
  • /
  • 2287-6251(eISSN)
한국초전도저온학회 (The Korean Society of Superconductivity and Cryogenics)
권호 표지
DOI QR코드

DOI QR Code

Realization of T-phase electron-doped cuprate oxide via polar discontinuity

  • 투고 : 2026.05.29
  • 심사 : 2026.06.20
  • 발행 : 2026.06.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

Electron-doped cuprates have mainly been studied in the T' structure because chemical electron doping tends to destabilize the T phase. Here, we realize electron-doped T-phase La2CuO4 (LCO) monolayers using polar discontinuity at oxide interfaces. Charging-free LCO/LAO/LSCO heterostructures were fabricated by pulsed laser deposition and studied by ARPES. The LCO monolayer exhibits a clear Fermi surface, unlike insulating bulk-like LCO, indicating successful electron doping. Tight-binding analysis shows that the electron doping level increases with LAO buffer-layer thickness, consistent with charge redistribution driven by polar discontinuity. However, thicker LAO layers also degrade the ARPES spectral quality, suggesting additional compensation mechanisms such as surface reconstruction. These results demonstrate polar discontinuity as a promising route to electron-doped T-phase cuprates.

키워드

과제정보

This work is supported by the Global Research Development Center (GRDC) Cooperative Hub Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (MSIT) (Grant No. RS-2023-00258359) and the NRF grant funded by the Korean government (MSIT) (Grant No. NRF-2022R1A3B1077234).

참고문헌

  1. T. Kondo, et al., "Competition between the pseudogap and superconductivity in the high-Tc copper oxides," Nature, vol. 457, no. 7227, pp. 296-300, 2009. https://doi.org/10.1038/nature07644
  2. E. H. da Silva Neto, et al., "Ubiquitous interplay between charge ordering and high-temperature superconductivity in cuprates," Science, vol. 343, no. 6169, pp. 393-396, 2014. https://doi.org/10.1126/science.1243479
  3. H. Saadaoui, et al., "The phase diagram of electron-doped La₂₋ₓCeₓCuO4₋δ," Nature Communications, vol. 6, no. 1, Art. no. 6041, 2015. https://doi.org/10.1038/ncomms7041
  4. Y. Tokura, H. Takagi, and S. Uchida, "A superconducting copper oxide compound with electrons as the charge carriers," Nature, vol. 337, no. 6205, pp. 345-347, 1989. https://doi.org/10.1038/337345a0
  5. M. Naito, S. Karimoto, and A. Tsukada, "Epitaxy-stabilized n-type superconducting cuprates," Superconductor Science and Technology, vol. 15, no. 12, pp. 1663-1668, 2002. https://doi.org/10.1088/0953-2048/15/12/306
  6. N. P. Armitage, P. Fournier, and R. L. Greene, "Progress and perspectives on electron-doped cuprates," Reviews of Modern Physics, vol. 82, no. 3, pp. 2421-2487, 2010.
  7. D. Song, et al., "Electron number-based phase diagram of Pr₁₋ₓLaCeₓCuO₄₋δ and possible absence of disparity between electron- and hole-doped cuprate phase diagrams," Physical Review Letters, vol. 118, no. 13, Art. no. 137001, 2017.
  8. H. I. Wei, et al., "Electron doping of the parent cuprate La₂CuO₄ without cation substitution," Physical Review Letters, vol. 117, no. 14, Art. no. 147002, 2016.
  9. N. Nakagawa, H. Y. Hwang, and D. A. Muller, "Why some interfaces cannot be sharp," Nature Materials, vol. 5, no. 3, pp. 204-209, 2006. https://doi.org/10.1038/nmat1569
  10. C. W. Schneider, et al., "Microlithography of electron gases formed at interfaces in oxide heterostructures," Applied Physics Letters, vol. 89, no. 12, Art. no. 122101, 2006.
  11. Y. Kim, et al., "Growth and electronic structure of copper oxide monolayer epitaxial films," Nano Letters, vol. 23, no. 16, pp. 7273-7278, 2023. https://doi.org/10.1021/acs.nanolett.3c00994
  12. A. Tsukada, T. Greibe, and M. Naito, "Phase control of La2CuO4 in thin film synthesis," Physical Review B, vol. 66, no. 18, Art. no. 184515, 2002. https://doi.org/10.1103/PhysRevB.66.184515
  13. J. Kim, et al., "Defect engineering in A2BO4 thin films via surfacereconstructed LaSrAlO₄ substrates," Small Methods, vol. 6, no. 11, Art. no. 2200880, 2022.