Graphene quantum dots are promising candidates for qubits due to weak spin-orbit and hyperfine interactions. The hyperfine interaction, controllable via isotopic purification, could be the key to further improving the coherence. Here, we use isotopically enriched graphite crystals of both 12C and 13C grown by high-pressure-high-temperature method to exfoliate graphene layers. We fabricated Hall bar devices and performed quantum transport measurements, revealing mobilities exceeding 105cm2/Vs and a long mean free path of microns, which are as high as natural graphene. Shubnikov-de Haas oscillations, quantum Hall effect up to the filling factor of one, and Brown-Zak oscillations due to the alignment of hBN and graphene are observed thanks to the high mobility. These results constitute a material platform for physics and engineering of isotopically-enriched graphene qubits.
@article{arxiv.2308.08175,
title = {High mobility transport in isotopically-enriched $^{12}$C and $^{13}$C exfoliated graphene},
author = {Shuichi Iwakiri and Jakob Miller and Florian Lang and Jakob Prettenthaler and Takashi Taniguchi and Kenji Watanabe and Sung Sik Lee and Pascal Becker and Detlef Günther and Thomas Ihn and Klaus Ensslin},
journal= {arXiv preprint arXiv:2308.08175},
year = {2024}
}