Quantum simulators for continuous-variable systems

State of the art and motivations A major barrier to our understanding of quantum many-body systems is the inherent difficulty in their simulation with a classical computer. One of Feynman’s remarkable insight [1] was that this problem can be overcome by harnessing other quantum systems, over which refined control is possible — namely, using them as “quantum simulators ” of the system of interest [2]. In other words, a quantum simulator is a “special-purpose ” quantum information processor whose physical interactions are engineered to simulate the working of another quantum system. As it has been noted, with the current performances of classical computers, we cannot even simulate an arbitrary system composed of just 40 spins (i.e., two-level quantum systems). Thus, even a special-purpose quantum computer, such as a quantum simulator, could allow us to overcome such an obstacle and explore novel quantum many-body physics — without the need of a fully fledged quantum computer. The above-mentioned obstacle is even more problematic if one deals with infinite-dimensional systems (also called continuous-variable systems) rather than with spins. However, little effort has been devoted to quantum simulators in this continuous-variable scenario — a situation whic