Machine-Learned Tuning to Protected States by Probing Noise Resilience

Protected states are promising for quantum technologies due to their intrinsic resilience against noise. However, such states often emerge at discrete points or small regions in parameter space and are, thus, difficult to find in experiments. In this Letter, we present a machine-learning method for tuning to protected regimes based on injecting noise into the system and searching directly for the most noise-resilient configuration. We illustrate this method by considering short quantum dot-based Kitaev chains, which we subject to random parameter fluctuations. Using the covariance matrix adaptation evolutionary strategy, we minimize the typical resulting ground state splitting, which makes the system converge to a protected configuration with well-separated Majorana bound states. We verify the robustness of our method by considering finite Zeeman fields, electron-electron repulsion, and asymmetric couplings and by varying the length of the Kitaev chain. Our Letter provides a reliable method for tuning to protected states including, but not limited to, isolated Majorana bound states.