Figure 1

Adaptive quantum phase estimation scheme. A qubit m is injected into the quantum circuit either in the quantum state \(|0\rangle \) or \(|1\rangle \) and its measured outcome \(\zeta _{m} \in \{0,1\}\) is used together with some policy phase instruction \(x_{m} \in \mathopen [0,2\pi \mathclose [\) to prepare the circuit for the next round of measurements. The quantum circuit consists of two Hadamard gates H, a phase shift gate \(\mathrm{U}_{\phi ,\theta }\), a detector D, and a processing unit with phase update instructions for the controllable phase shifter