Engineering strong beamsplitter interaction between bosonic modes via quantum optimal control theory
Basilewitsch D, Zhang Y, Girvin SM, Koch C (2022)
Publication Type: Journal article
Publication year: 2022
Journal
Book Volume: 4
Article Number: 023054
Journal Issue: 2
DOI: 10.1103/PhysRevResearch.4.023054
Abstract
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.
Involved external institutions
Germany (DE)
United States (USA) (US)How to cite
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://dx.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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