Lindblad estimation with fast and precise quantum control

In quantum metrology, Lindblad estimation spans a host of applications, from probing weak stochastic signals to noise spectroscopy and characterization of emerging technologies. Regrettably, the ultimate quantum limits of Lindblad estimation are not understood in general. By examining the performance of the optimal sequential strategy that can simulate any other metrological strategy, the authors show that it is best to rapidly projectively measure and reinitialize the quantum state. This protocol may accelerate searches for stochastic gravitational waves, quantum gravity, and axionic dark matter, and also may enhance noise spectroscopy with qubits and Pauli Lindblad estimation.