Using inelastic cotunneling spectroscopy we observe a zero field splitting within the spin triplet manifold of Ge hut wire quantum dots. The states with spin ±1 in the confinement direction are energetically favored by up to 55 μeV compared to the spin 0 triplet state because of the strong spin–orbit coupling. The reported effect should be observable in a broad class of strongly confined hole quantum-dot systems and might need to be considered when operating hole spin qubits.
We acknowledge G. Burkard, V. N. Golovach, C. Kloeffel, D.Loss, P. Rabl, and M. Rancič ́ for helpful discussions. We further acknowledge T. Adletzberger, J. Aguilera, T. Asenov, S. Bagiante, T. Menner, L. Shafeek, P. Taus, P. Traunmüller, and D. Waldhausl for their invaluable assistance. This research was supported by the Scientific Service Units of IST Austria through resources provided by the MIBA Machine Shop and the nanofabrication facility, by the FWF-P 32235 project, by the National Key R&D Program of China (2016YFA0301701, 2016YFA0300600), and by the European Union’s Horizon 2020 research and innovation program under grant agreement no. 862046. All data of this publication are available at 10.15479/AT:ISTA:7689.
Katsaros G, Kukucka J, Vukušić L, et al. Zero field splitting of heavy-hole states in quantum dots. Nano Letters. 2020;20(7):5201-5206. doi:10.1021/acs.nanolett.0c01466
Katsaros, G., Kukucka, J., Vukušić, L., Watzinger, H., Gao, F., Wang, T., … Held, K. (2020). Zero field splitting of heavy-hole states in quantum dots. Nano Letters. ACS Publications. https://doi.org/10.1021/acs.nanolett.0c01466
Katsaros, Georgios, Josip Kukucka, Lada Vukušić, Hannes Watzinger, Fei Gao, Ting Wang, Jian-Jun Zhang, and Karsten Held. “Zero Field Splitting of Heavy-Hole States in Quantum Dots.” Nano Letters. ACS Publications, 2020. https://doi.org/10.1021/acs.nanolett.0c01466.
G. Katsaros et al., “Zero field splitting of heavy-hole states in quantum dots,” Nano Letters, vol. 20, no. 7. ACS Publications, pp. 5201–5206, 2020.
Katsaros G, Kukucka J, Vukušić L, Watzinger H, Gao F, Wang T, Zhang J-J, Held K. 2020. Zero field splitting of heavy-hole states in quantum dots. Nano Letters. 20(7), 5201–5206.
Katsaros, Georgios, et al. “Zero Field Splitting of Heavy-Hole States in Quantum Dots.” Nano Letters, vol. 20, no. 7, ACS Publications, 2020, pp. 5201–06, doi:10.1021/acs.nanolett.0c01466.
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