Effect of qubit losses on Grover’s quantum search algorithm

摘要

We investigate the performance of Grover’s quantum search algorithm on a register that is subject to a lossnof particles that carry qubit information. Under the assumption that the basic steps of the algorithm are appliedncorrectly on the correspondingly shrinking register, we show that the algorithm converges to mixed states withn50% overlap with the target state in the bit positions still present. As an alternative to error correction, we presentna procedure that combines the outcome of different trials of the algorithm to determine the solution to the fullnsearch problem. The procedure may be relevant for experiments where the algorithm is adapted as the lossnof particles is registered and for experiments with Rydberg blockade interactions among neutral atoms, wherenmonitoring of atom losses is not even necessary.