W59.00007 . Higher harmonics of quantum oscillations uncover Dirac Fermons in LaRhIn5

Presented by: Aris Alexandradinata


Abstract

Quantum oscillations are commonly used to experimentally diagnose the band topology of a semimetal. When the cyclotron orbit encloses a topological defect, it is often presumed that the nontrivial Berry phase results in a π-phase shift of the fundamental harmonic. However, this presumption neglects how spin-orbit coupling renders the Berry phase a continuously varying quantity, and ignores the Zeeman interaction with the spin-orbit-induced magnetic moment. Here, we overcome these shortcomings and demonstrate how to rigorously identify three-dimensional Dirac fermions from the higher harmonics of quantum oscillations. Applying this method to the intermetallic LaRhIn5, we unambiguously identify the nontrivial Berry phase of a topological Fermi pocket with a small frequency ≈ 7T, despite the presence of large, trivial Fermi pockets which dominate transport by orders of magnitude. Our analysis identifies LaRhIn5 as a 3D Dirac-point metal, revising a previous proposal of LaRhIn5 as a nodal-line semimetal by Mikitik et. al. [Phys. Rev. Lett. 93, 106403 (2004)]. The electronic similarity of LaRhIn5 to the prototypical heavy-fermion superconductors Ce(Co,Rh,Ir)In5 further suggests them as prime candidates for strongly-correlated Dirac systems.

Authors

  • Aris Alexandradinata
  • Chunyu Guo
  • Carsten Putzke
  • Fengren Fan
  • Shengnan Zhang
  • QuanSheng Wu
  • Oleg V. Yazyev
  • Kent Shirer
  • Maja Bachmann
  • Eric Bauer
  • Filip Ronning
  • Claudia Felser
  • Yan Sun
  • Philip Moll


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