Emergence of a Kondo singlet state with Kondo temperature well beyond 1000 K in a proton-embedded electron gas

• Takada, Yasutami

• Maezono, Ryo

• Yoshizawa, Kanako

Abstract

Hydrogen in metals has attracted much attention for a long time from both basic scientific and technological points of view. Its electronic state has been investigated in terms of a proton embedded in the electron gas mostly by the local density approximation (LDA) to the density functional theory. At high electronic densities, it is well described by a bare proton H^+ screened by metallic electrons (charge resonance), while at low densities two electrons are localized at the proton site to form a closed-shell negative ion H^− protected from surrounding metallic electrons by the Pauli exclusion principle. However, no details are known about the transition from H^+ to H^− in the intermediate-density region. Here, by accurately determining the ground-state electron distribution n(r) by the use of LDA and diffusion Monte Carlo simulations with the total electron number up to 170, we obtain a complete picture of the transition, in particular, a sharp transition from short-range H^+ screening charge resonance to long-range Kondo-type spin-singlet resonance, the emergence of which is confirmed by the presence of an anomalous Friedel oscillation characteristic to the Kondo singlet state with the Kondo temperature T_K well beyond 1000 K. This study not only reveals interesting competition between charge and spin resonances, enriching the century-old paradigm of metallic screening to a point charge, but also discovers a high-T_K system long sought in relation to the development of exotic superconductivity in the quantum critical regime.

identifier:https://dspace.jaist.ac.jp/dspace/handle/10119/14214

Journal

• Physical Review B

  Physical Review B 92 (15), 155140-1-155140-11, 2015-10-23

  American Physical Society

Keywords

• Diffusion Monte Carlo
• Kondo singlet
• Jellium sphere
• Friedel oscillation

Details

• CRID: 1050282812515223424
• NII Article ID: 120006305707
• ISSN: 10980121
• Web Site: http://hdl.handle.net/10119/14214
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles