Correcting detection errors in quantum state engineering through data processing

Verifying correlations within a quantum state is an important task in quantum state engineering, while realistic detectors with imperfect efficiency usually introduce errors into the detection results. With these detection errors, genuine multi-partite entanglement can be invisible. In this paper, we propose a simple method for correcting arbitrary uncorrelated detection errors. The method is based on the processing of data from repetitive experiments and can correct detection errors of any magnitude as long as the error magnitude is calibrated. The method is illustrated with its application in the detection of multi-partite entanglement from quantum state engineering.