Anomalous High-Field Magnetotransport in CaFeAsF due to the Quantum Hall Effect

Taichi Terashima; Hishiro T. Hirose; Naoki Kikugawa; Shinya Uji; David Graf; Takao Morinari; Teng Wang; Gang Mu

doi:10.1038/s41535-022-00470-6

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arXiv · 2107.10460

Anomalous High-Field Magnetotransport in CaFeAsF due to the Quantum Hall Effect

Taichi Terashima·Hishiro T. Hirose·Naoki Kikugawa·Shinya Uji·David Graf·Takao Morinari·Teng Wang·Gang Mu

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Abstract

CaFeAsF is an iron-based superconductor parent compound whose Fermi surface is quasi-two dimensional, composed of Dirac-electron and Schr\"odinger-hole cylinders elongated along the $c$ axis. We measured the longitudinal and Hall resistivities in CaFeAsF with the electrical current in the $ab$ plane in magnetic fields up to 45 T applied along the $c$ axis and obtained the corresponding conductivities via tensor inversion. We found that both the longitudinal and Hall conductivities approached zero above $\sim$40 T as the temperature was lowered to 0.4 K. Our analysis indicates that the Landau-level filling factor is $\nu$ = 2 for both electrons and holes at these high field strengths, resulting in a total filling factor $\nu$ = $\nu_{hole} - \nu_{electron}$ = 0. We therefore argue that the $\nu$ = 0 quantum Hall state emerges under these conditions.

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Taichi Terashima, Hishiro T. Hirose, Naoki Kikugawa, Shinya Uji, David Graf, Takao Morinari, Teng Wang, Gang Mu. 2021-07-22. Anomalous High-Field Magnetotransport in CaFeAsF due to the Quantum Hall Effect. https://doi.org/10.1038/s41535-022-00470-6

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