Quantum Sensing and Hamiltonian Learning under Stochastic Parameter Evolution
The research explores learning unknown parameters in quantum systems where Hamiltonians change randomly over time (Stochastically Evolving Hamiltonians or SEHs). The authors developed new protocols, like Extended Robust Frequency Estimation, which can achieve the Heisenberg limit for precision. This means they can estimate the system's parameters with the highest possible accuracy allowed by quantum mechanics, even when the system's governing rules are noisy.