Analyzing the fidelity of a singlet-triplet spin-orbit qubit in silicon using gate set tomography

It has been recently demonstrated that spin-orbit effects observed in silicon quantum dots are much larger than what is expected for bulk silicon [1-3]. These spin-orbit effects can be used to achieve all-electrical universal control of a double quantum dot singlet-triplet qubit without the need for any external components, such as micromagnets or microwave resonators, to produce a magnetic field gradient [4]. In this work, we use gate set tomography to analyze the fidelity of these gates. We also explore the possibility of using AC control, both in the weak and strong driving regimes, to improve the fidelity of qubit operations.

This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the DOE’s National Nuclear Security Administration under contract DE-NA0003525

References
1. Jock et al., Nat. Commun. 9, 1768 (2018)
2. Tanttu et al., arXiv:1807.10415 (2018)
3. Harvey-Collard et al., arXiv:1808.07378 (2018)
4. Harvey-Collard et al., IEEE IEDM 36.5.1 (2017)