Spin Freezing Crossover and Cooper Pairing Symmetry in the Organic Strange Metal kappa-(ET)4Hg2.89Br8 and kappa-(ET)4Hg2.78Cl8

2022 Fiscal Year Research-status Report

• Project/Area Number: 21K13885
• Research Institution: Shibaura Institute of Technology
• Principal Investigator: Dita PuspitaSari 芝浦工業大学, 工学部, 助教 (00821919)
• Project Period (FY): 2021-04-01 – 2025-03-31
• Keywords: Penetration depth / Knight shift / strange metal / non-Fermi liquid

Outline of Annual Research Achievements

In this year we have performed Transverse-field muSR experiment on k-HgBr for the first time (in the perpendicular mode) obtaining in-plane penetration depth order parameter. The additional measurement is necessary to improve signal-noise ratio. We got our following muSR proposal approved and plan to add the sample mass.
In the k-HgCl Zero-field muSR measurement also has been done in k-HgCl down to 25 miliK for the first time. There is no obvious signature of long-range ordered.
Furthermore, we have developed a technique to measure dc-susceptibility for this series samples (plate-like shape crystal) to get a precise temperature dependence of susceptibility. We aim to report the plot of muon Knight shift vs susceptibility, comparing between those in k-HgBr and k-HgCl.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

The penetration depth measurement needs to be improved to get solid and complete data set, although we earned the high-priority muSR beamtime at TRIUMF Canada from the proposal submission in January 2023.

Strategy for Future Research Activity

2023: We will perform Transverse-field muSR at TRIUMF in k-HgBr. The measurement at ISIS and JPARC is slightly shifted to 2024.

2024: Writing up main papers and execute a continuation.

Research Products

• [Int'l Joint Research] TRIUMF(カナダ)
  • Country Name: CANADA
  • Counterpart Institution: TRIUMF
• [Int'l Joint Research] ISIS(英国)
  • Country Name: UNITED KINGDOM
  • Counterpart Institution: ISIS
• [Journal Article] Superconductivity nearby quantum critical region in hole-doped organic strange metal κ-(ET)₄Hg_3-δBr₈, δ=11% (2023)
  • Author(s): Sari D P、Kaito M、Someya Y、Widyaiswari U、Watanabe I、Taniguchi H、Ishii Y
  • Journal Title: Journal of Physics: Conference Series Volume: 2462 Pages: 012061～012061
  • DOI: 10.1088/1742-6596/2462/1/012061
  • Peer Reviewed
• [Presentation] Superconductivity Nearby Quantum Spin Liquid States in Doped Organic Metal (2022)
  • Author(s): D. P. Sari, Y. Cai, M-V. deToro Sanchez, K. M. Kojima, I. Watanabe, Y. Ishii, and H. Taniguchi
  • Organizer: The 13th International Conference on Materials and Mechanisms of Superconductivity (M2S 2022)
• [Presentation] Superconductivity Nearby Quantum Critical Point in Hole-Doped Organic Strange Metal -(ET)4Hg3-Br8 (2022)
  • Author(s): D. P. Sari, Y. Cai, U. Widyaiswari, E. Yamada, M-V. deToro Sanchez, Y. Someya, A. Koda, K. M. Kojima, I. Watanabe, Y. Ishii, and H. Taniguchi
  • Organizer: The 15th International Conference on Muon Spin Rotation, Relaxation and Resonance (muSR conference 2020)
• [Presentation] μ+SR Study of κ-(ET)4Hg3-δBr8 (δ=0.11) and κ-(ET)4Hg3-δCl8 (δ=0.22) Part II (2022)
  • Author(s): D. P. Sari, Y. Cai, U. Widyaiswari, E. Yamada, M-V. deToro Sanchez, Y. Someya, A. Koda, K. M. Kojima, I. Watanabe, Y. Ishii, and H. Taniguchi
  • Organizer: JPS Autumn Meeting 2022
• [Presentation] μ+SR Study of κ-(ET)4Hg2.89Br8 and κ-(ET)4Hg2.78Cl8 (2022)
  • Author(s): 4.1.15D. P. Sari, Y. Cai, U. Widyaiswari, E. Yamada, M-V. deToro Sanchez, Y. Someya, K. M. Kojima, I. Watanabe, H. Taniguchi and Y. Ishii
  • Organizer: The 6th International Conference on Functional Materials Science (ICFMS 2022)