Quantum annealing in capacitively-coupled Kerr parametric oscillators using frequency-chirped drives

A network of Kerr Parametric Oscillators (KPOs) can act as a quantum annealer whose Ising Hamiltonian can be controlled via one-photon drives and couplings of KPOs [1]. We experimentally study simultaneous parametric oscillations in a system composed of two capacitively-coupled KPOs using one-photon and two-photon drives with frequency chirping. We examine quantum adiabatic dynamics of the system especially focusing on an effect of chirped one-photon and two-photon drives on efficiency of quantum annealing. The oscillation frequency is negatively detuned from the resonance frequency at the start of the parametric modulation to enable the adiabatic evolution from the initial (vacuum) state and then chirped toward the resonance frequency as we increase the parametric modulation to reach the final state with the lowest Ising energy. We demonstrate controls of the Ising Hamiltonian and show that chirped drives can enhance the efficiency of quantum annealing compared to our previous method without chirping [2, 3]. The present result demonstrates the effectiveness of chirping in a quantum annealer made of a network of KPOs.

[1] H. Goto, Sci. Rep. 6, 21686 (2016).

[2] T. Yamaji et al., Phys. Rev. A 105, 023519 (2022).

[3] T. Yamaji et al., Phys. Rev. Applied 20, 014057 (2023).