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arXiv · 2312.15783

Universal Control in Bosonic Systems with Weak Kerr Nonlinearities

Ming Yuan·Alireza Seif·Andrew Lingenfelter·David I. Schuster·Aashish A. Clerk·Liang Jiang
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Abstract

Resonators with weak single-photon self-Kerr nonlinearities can theoretically be used to prepare Fock states in the presence of a loss much larger than their nonlinearities. Two necessary ingredients are large displacements and a two-photon (parametric) drive. Here, we find that these systems can be controlled to achieve any desired gate operation in a finite dimensional subspace (whose dimensionality can be chosen at will). Moreover, we show that the two-photon driving requirement can be relaxed and that full controllability is achievable with only 1-photon (linear) drives. We make use of both Trotter-Suzuki decompositions and gradient-based optimization to find control pulses for a desired gate, which reduces the computational overhead by using a small blockaded subspace. We also discuss the infidelity arising from input power limitations in realistic settings, as well as from corrections to the rotating-wave approximation. Our universal control protocol opens the possibility for quantum information processing using a wide range of lossy systems with weak nonlinearities.

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Ming Yuan, Alireza Seif, Andrew Lingenfelter, David I. Schuster, Aashish A. Clerk, Liang Jiang. 2023-12-25. Universal Control in Bosonic Systems with Weak Kerr Nonlinearities. https://doi.org/10.1103/physreva.111.032606

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