Wydarzenia

Seminarium Oddziału Badań Magnetyków

Low-frequency quantum oscillations in LaRhIn5: Dirac point or a nodal line?

dr Yuriy Sharlai

Fizyko-Techniczny Instytut Niskich Temperatur im. B. Verkina Narodowej Akademii Nauk Ukrainy w Charkowie

Seminarium odbędzie się zdalnie w aplikacji Microsoft Teams. W celu wzięcia udziału w wydarzeniu należy dołączyć do zespołu Seminarium OBM. Można do niego dołączyć na stałe przy użyciu kodu dostępu ol7omod (dotyczy to osób posiadających konto w domenie intibs.pl, pozostałe osoby proszę o kontakt z prof. dr. hab.Adamem Pikulem, prof. INTiBS PAN ())

The seminar will be held remotely in the Microsoft Teams application. In order to participate in the event, you must join the Seminarium OBM team. You can join it permanently using the access code ol7omod (this applies to people with an account in the intibs.pl domain, other people please contact Prof. Adam Pikul , Prof. INTiBS PAN ())

Abstract:

In a recent paper Guo et al. [1] proposed a new method for detecting charge carriers with a linear energy-band dispersion characteristic of the topological materials. The method is based on measuring a temperature correction to a quantum-oscillation frequency. In particular, Guo and coauthors detected such carriers in LaRhIn5. These carriers exhibit oscillations with the frequency F  7 T, and Guo et al. attributed these  oscillations to a Fermi-surface pocket surrounding a Dirac point. On the other hand, many years ago [2], we argued that the charge carriers with F = 7 T are located near a nodal line in LaRhIn5 rather than near a Dirac point. 
In the talk based on the recent paper [3], I will explain that the main experimental result of Guo et al. does not contradict our assumption of the nodal line. Although the method of Ref.[1] really detects charge carriers with linear dispersion, it does not distinguish between the carriers near a Dirac point and near a nodal line, since all such quasiparticles disperse linearly. Moreover, the assumption of the Dirac point cannot explain the data of Goodrich et al. [4] on the magnetization of this metal. However, Guo et al. [1] found independence of the frequency F of the Shubnikov{de Haas oscillations on the direction of the magnetic field. This result is inconsistent with the nodal-line assumption. Thus, at present, the nature of the charge carriers in LaRhIn5 remains mysterious, and I call attention to this puzzling situation.

[1] Guo, C. et al. Temperature dependence of quantum oscillations from non-parabolic dispersion. Nat. Commun.
12, 6213 (2021).
[2] Mikitik, G. P. & Sharlai, Yu. V. Berry phase and de Haas - van Alphen eect in LaRhIn5. Phys. Rev. Lett. 93,
106403 (2004).
[3] Mikitik, G.P., Sharlai, Yu.V. Low-frequency quantum oscillations in LaRhIn5: Dirac point or nodal line?. Nat.
Commun. 14, 2060 (2023).
[4] Goodrich, R.G. et al. Magnetization in the ultraquantum limit. Phys. Rev. Lett. 89, 026401 (2002).