Coexistence of Logarithmic and SdH Quantum Oscillations in Ferromagnetic Cr-doped Tellurium Single Crystals

TL;DR

This study synthesizes ferromagnetic Cr-doped tellurium single crystals exhibiting coexistence of logarithmic and SdH quantum oscillations, revealing broken symmetry in Fermi pockets and potential for quantum material applications.

Contribution

It demonstrates the simultaneous presence of logarithmic and SdH quantum oscillations in ferromagnetic Cr-doped tellurium, a novel elemental quantum material.

Findings

Cr-doped tellurium shows ferromagnetism and high Hall mobility.

Coexistence of logarithmic and SdH oscillations depending on magnetic field direction.

Broken rotation symmetry of Fermi pockets inferred from oscillation behavior.

Abstract

We report the synthesis of transition-metal-doped ferromagnetic elemental single-crystal semiconductors with quantum oscillations using the physical vapor transport method. The 7.7 atom% Cr-doped Te crystals (Cr_Te) show ferromagnetism, butterfly-like negative magnetoresistance in the low temperature (< 3.8 K) and low field (< 0.15 T) region, and high Hall mobility, e.g., 1320 cm2 V-1 s-1 at 30 K and 350 cm2 V-1 s-1 at 300 K, implying that Cr_Te crystals are ferromagnetic elemental semiconductors. When B // c // I, the maximum negative MR is -27% at T = 20 K and B = 8 T. In the low temperature semiconducting region, Cr_Te crystals show strong discrete scale invariance dominated logarithmic quantum oscillations when the direction of the magnetic field B is parallel to the [100] crystallographic direction and show Landau quantization dominated Shubnikov-de Haas (SdH) oscillations for B // [210] direction, which suggests the broken rotation symmetry of the Fermi pockets in the Cr_Te crystals. The findings of coexistence of multiple quantum oscillations and ferromagnetism in such an elemental quantum material may inspire more study of narrow bandgap semiconductors with ferromagnetism and quantum phenomena.