Since very few Type-I superconductors are known and most are elemental superconductors, there are very few experimental platforms where the interaction between Type-I superconductivity and topologically nontrivial band structure can be probed. The rhenium aluminide Al6Re has recently been identified as a Type-I superconductor with a transition of 0.74\,K and a critical field of ∼50\,Oe. Here, we report its magnetotransport behavior including de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) oscillations. Angular dependence of the magnetoresistance reveals a highly anisotropic Fermi surface with dominant hole character. From the strong oscillatory component ΔRxx in high magnetic fields up to 33\,T, the Landau index infinite-field intercept in the case of a single oscillation frequency, and the phase factor φ where multiple frequencies coexist, are both ∼1/4. This intermediate value is suggestive of possible nontrivial band topology but does not allow strong conclusions.
@article{arxiv.1904.09893,
title = {Magnetotransport in Al6Re},
author = {Erjian Cheng and Darren C. Peets and Chuanying Xi and Yeyu Huang and Li Pi and Shiyan Li},
journal= {arXiv preprint arXiv:1904.09893},
year = {2019}
}