Understanding the nature of magnetism in the Van der Waals Material TaCo₂Te₂ using diamond quantum sensors

TaCo₂Te₂ is an air-stable van der Waals (vdW) material with high mobility carriers making it a promising candidate for novel low-dimensional devices. Despite reports of probable magnetic order¹, the exact nature of the magnetism remains elusive due to the absence of any magnetic phase transitions below 300K as well as the very weak magnetic moment observed under applied fields of 7T. Recent high temperature measurements have revealed two phase transitions in the susceptibility data above room temperature. While one has been identified to be the Peierls distortion known to arise within this material, the other, which occurs between 380-400K, remains to be fully characterized. This is in part due to a lack of accessible probes for studying 2D magnetic systems in this regime. In this work we explore the application of nitrogen vacancy (NV) centers in diamond as nanoscale probes of magnetic noise to elucidate the potential magnetism in TaCo₂Te_2.

[1] R. Singha, F. Yuan, G. Cheng, T. H. Salters, Y. M. Oey, G. V. Villalpando, M. Jovanovic, N. Yao, L. M. Schoop, TaCo₂Te₂: An Air-Stable, High Mobility Van der Waals Material with Probable Magnetic Order. Adv. Funct. Mater. 2022, 32, 2108920. https://doi.org/10.1002/adfm.202108920