Learning Many-Body Hamiltonians Using a Local Probe
The study shows that a single measurable qubit can learn all parameters of a bounded-degree two-body Hamiltonian across N qubits at the Heisenberg limit. This is achieved by using Hamiltonian reshaping to isolate local terms and robust phase estimation to extract unknown coefficients. The method allows for scalable learning of many-body interactions through only local measurements, offering an efficient route for quantum parameter estimation.