• Rapid Communication

Microscopic mechanism of room-temperature superconductivity in compressed LaH10

Liangliang Liu, Chongze Wang, Seho Yi, Kun Woo Kim, Jaeyong Kim, and Jun-Hyung Cho
Phys. Rev. B 99, 140501(R) – Published 4 April 2019
PDFHTMLExport Citation

Abstract

Room-temperature superconductivity has been one of the most challenging subjects in modern physics. Recent experiments reported that lanthanum hydride LaH10±x (x<1) raises a superconducting transition temperature Tc up to 260 (or 250) K at high pressures around 190 (170) GPa. Here, based on first-principles calculations, we reveal that compressed LaH10 has symmetry-protected Dirac-nodal-line states, which split into holelike and electronlike bands at the high-symmetry points near the Fermi energy (EF), thereby producing a van Hove singularity (vHs). The crystalline symmetry and the band topology around the high-symmetry points near EF are thus demonstrated to be important for room-temperature superconductivity. Further, we identify that the electronic states at the vHs are composed of strongly hybridized La f and H s orbitals, giving rise to a peculiar characteristic of electrical charges with anionic La and both anionic and cationic H species. Consequently, a large number of electronic states at the vHs are strongly coupled to the H-derived high-frequency phonon modes that are induced via the unusual, intricate bonding network of LaH10, therefore yielding a high Tc. Our findings elucidate the microscopic mechanism of the observed high-Tc BCS-type superconductivity in LaH10, which can be generic to another recently observed high-Tc hydride H3S.

  • Figure
  • Figure
  • Figure
  • Figure
  • Received 11 November 2018
  • Revised 22 March 2019

DOI:https://doi.org/10.1103/PhysRevB.99.140501

©2019 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Liangliang Liu1,2, Chongze Wang1, Seho Yi1, Kun Woo Kim3, Jaeyong Kim1, and Jun-Hyung Cho1,*

  • 1Department of Physics, Research Institute for Natural Science, and HYU-HPSTAR-CIS High Pressure Research Center, Hanyang University, 222 Wangsimni-ro, Seongdong-Ku, Seoul 04763, Republic of Korea
  • 2Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004, People's Republic of China
  • 3Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon 34051, Republic of Korea

  • *Corresponding author: chojh@hanyang.ac.kr

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 99, Iss. 14 — 1 April 2019

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×