Digital quantum simulation of beam splitters and squeezing with IBM quantum computers

We present results on the digital quantum simulations of beam-splitter and squeezing interactions. The bosonic hamiltonians are mapped to qubits and then digitalized in order to implement them in the IBM quantum devices. We use error mitigation and post-selection to achieve high-fidelity digital quantum simulations of single-mode and two-mode interactions, as evidenced – where possible – by full tomography of the resulting states. We achieve fidelities above 90 % in the case of single-mode squeezing with low squeezing values and ranging from 60 % to 90 % for large squeezing and in the more complex two-mode interactions.