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Seminaire le 30 mai

par Hervé Henry - publié le

Jeudi 30 mai à 11h en salle de sémiaire PMC

Gaël Grissonnanche (LSI )
Chiral phonons in quantum materials revealed by the thermal Hall effect

It is becoming surprisingly clear that phonons can produce a large thermal Hall effect across a wide range of quantum materials, from cuprate superconductors [1,2] to titanates [3], iridates [4], and frustrated magnets [5]. The thermal Hall effect represents the deflection of a heat current by a perpendicular magnetic field. It is usually interpreted as coming from mobile hot electrons deflected by the Lorentz force. While trivial in metals, this effect is now found in insulators, and phonons that carry no charge are responsible for it. Phonons are the most common low-energy excitations in solids. Yet the handedness they acquire in a magnetic field – which triggers the thermal Hall effect – remains an enigma that fuels experimental and theoretical developments. In this talk, I will present the results that have led to the emergence of a new field of research aimed at discovering the origin of the thermal Hall effect of phonons and how this might relate to the question of chiral phonons measured by other probes.

  1. [1] Grissonnanche et al. Nature 571, 376 (2019)
  2. [2] Grissonnancheet al. Nat. Phys. 16, 1108 (2020)
  3. [3]Li et al. Phys. Rev. Lett. 124, 105901 (2020)
  4. [4]Ataei et al. Nat. Phys. 20, 585 (2024)
  5. [5] Lefrançois et al. Phys. Rev. X 12, 021025 (2022)