Basilewitsch D, Zhang Y, Girvin SM, Koch C (2022)
Publication Type: Journal article
Publication year: 2022
Book Volume: 4
Article Number: 023054
Journal Issue: 2
DOI: 10.1103/PhysRevResearch.4.023054
In continuous-variable quantum computing with qubits encoded in the infinite-dimensional Hilbert space of bosonic modes, it is a difficult task to realize strong and on-demand interactions between the qubits. One option is to engineer a beamsplitter interaction for photons in two superconducting cavities by driving an intermediate superconducting circuit with two continuous-wave drives, as demonstrated in a recent experiment [Gao, Phys. Rev. X 8, 021073 (2018)10.1103/PhysRevX.8.021073]. Here we show how quantum optimal control theory (OCT) can be used in a systematic way to improve the beamsplitter interaction between the two cavities. We find that replacing the two-tone protocol by a three-tone protocol accelerates the effective beamsplitter rate between the two cavities. The third tone's amplitude and frequency are determined by gradient-free optimization and make use of cavity-transmon sideband couplings. We show how to further improve the three-tone protocol via gradient-based optimization while keeping the optimized drives experimentally feasible. Our work exemplifies how to use OCT to systematically improve practical protocols in quantum information applications.
APA:
Basilewitsch, D., Zhang, Y., Girvin, S.M., & Koch, C. (2022). Engineering strong beamsplitter interaction between bosonic modes via quantum optimal control theory. Physical Review Research, 4(2). https://doi.org/10.1103/PhysRevResearch.4.023054
MLA:
Basilewitsch, Daniel, et al. "Engineering strong beamsplitter interaction between bosonic modes via quantum optimal control theory." Physical Review Research 4.2 (2022).
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