Beyond Boson Sampling: Higher Spin Sampling as a Practical Path to Quantum Supremacy

Abstract: Since the dawn of quantum computation science, a range of quantum algorithms have been proposed, yet few have experimentally demonstrated a definitive quantum advantage. Shor's algorithm, while renowned, has not been realized at a scale to outperform classical methods. In contrast, Fock-state boson sampling has been theoretically established as a means of achieving quantum supremacy. However, most existing experimental realizations of boson sampling to date have been based on Gaussian boson sampling, in which the input states consist of squeezed states of light. In this work, we first introduce spin sampling for arbitrary spin-$S$ states as a practical path to quantum supremacy. We identified a quasi-linear scaling relation between the number of sites $m$ and the number of spins $n$ as $m\sim n^{1+\epsilon}$, where $\epsilon=3/(2S)$ is inversely proportional to the spin quantum number. This suggests that, within a spin system, an equivalent Fock-state boson sampling task in the linear mode region, characterized by $m\sim \Omega(n^{1+\epsilon})$, is experimentally feasible with reduced resource requirements.