Multiphoton Quantum Reservoirs For Robust Multidimensional Computing.

One of the most significant achievements of the second quantum revolution is enabling tasks that are infeasible for classical computers. However, the stringent requirements for quantum resources, along with the presence of noise and losses, impose limitations on technologies for quantum information processing. Here, we overcome these limitations by demonstrating robust and scalable quantum reservoirs for multiphoton quantum computing, the first of their kind to operate robustly at room temperature under high levels of noise and decoherence. By implementing Fock projective measurements, we extract multiphoton quantum systems from classical fields, enabling the engineering of quantum reservoirs that are robust to losses and noise. Our multiphoton reservoirs support universal quantum information processing with up to forty particles, exhibiting quantum speedups over classical counterparts. Remarkably, the multiparticle interactions hosted by our reservoirs enable us to perform quantum simulations of nonlinear systems. Specifically, we simulate the quantum thermodynamics of many-body systems in synthetic lattices. Furthermore, we exploit the complexity of our multiphoton quantum reservoir, consisting of eight hundred sixty-one components, for the quantum prediction of mathematical functions. As such, our work unveils a path toward the development of robust quantum technologies for information processing, long regarded as a central goal of the field.