Abstract Coherent Ising machine (CIM) is a network of optical parametric oscillators that can solve large-scale combinatorial optimisation problems by finding the ground state of an Ising Hamiltonian. As a practical application of CIM. Aonishi et al. proposed a quantum-classical hybrid system to solve optimisation problems of $$l_0$$ l 0 -regularisation-based compressed sensing. https://www.ealisboa.com/limited-value-AXYS-Valhalla-Pen-must-buy/