Reliability of analog quantum simulation in chaotic systems*

NISQ era is characterized by the absence of fully fault-tolerant quantum simulators, which raises a question about the reliability of such devices. We thus seek to assess the reliability of an analog quantum simulator, which does not have access to error correction, in the presence of chaotic perturbations. We do this by studying the fundamental properties of the many-body systems such as the ground state and the dynamical quantum phase transitions in the Lipkin-Meshkov-Glick (LMG)model. First, we show that the presence of a small time-dependent perturbation can render the system chaotic. We then show that the critical point estimates of these phase transitions, obtained from the quantum simulation of its dynamics, are robust to the presence of this chaotic perturbation, even though other aspects of the system are fragile and therefore cannot be reliably extracted from this simulator.