2021/08/06 by Yuanji Xu, Yutao Sheng, Yi-feng Yang +1
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Delocalized electron #Electron #Fermi liquid theory #Ground state #Magnetic and transport properties of perovskites and related materials #Mott insulator #Pairing #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum critical point #Quantum mechanics #Quantum phase transition #Strongly correlated material #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1038/s41535-022-00429-7
published as npj Quantum Mater. 7, 21 (2022) · 6 pages, 4 figures
arxiv created 2021/08/06 · openalex created_date 2021/08/16 · openalex publication_date 2022/02/14 · arxiv updated 2022/02/16 · openalex updated_date 2026/08/05
Abstract The quantum spin liquid candidate NaYbSe 2 was recently reported to exhibit a Mott transition under pressure. Superconductivity was observed in the high-pressure metallic phase, raising the question concerning its relation with the low-pressure quantum spin liquid ground state. Here we combine the density functional theory and the dynamical mean-field theory to explore the underlying mechanism of the insulator-to-metal transition and superconductivity and establish an overall picture of its electronic phases under pressure. Our results suggest that NaYbSe 2 is a charge-transfer insulator at ambient pressure. Upon increasing pressure, however, the system first enters a semi-metallic state with incoherent Kondo scattering against coexisting localized Yb-4 f moments, and then turns into a heavy-fermion metal. In between, there may exist a delocalization quantum critical point responsible for the observed non-Fermi liquid region with linear-in- T resistivity. The insulator-to-metal transition is therefore a two-stage process. Superconductivity emerges in the heavy-fermion phase with well-nested Yb-4 f Fermi surfaces, suggesting that spin fluctuations may play a role in the Cooper pairing. NaYbSe 2 might therefore be the 3rd Yb-based heavy-fermion superconductor with a very “high” T c than most heavy-fermion superconductors.