Nonlocality enhanced precision in quantum polarimetry via entangled photons

Abstract

A nonlocal quantum approach is presented to polarimetry, leveraging the phenomenon of entanglement in photon pairs to enhance the precision in sample property determination. By employing two distinct channels, one containing the sample of interest and the other serving as a reference, the conditions are explored under which the inherent correlation between entangled photons can increase measurement sensitivity. Specifically, the quantum Fisher information (QFI) is calculated and compare the accuracy and sensitivity for the cases of single sample channel versus two channel quantum state tomography measurements. The theoretical results are verified by experimental analysis. The theoretical and experimental framework demonstrates that the nonlocal strategy enables enhanced precision and accuracy in extracting information about sample characteristics more than the local measurements. Depending on the chosen estimators and noise channels present, theoretical and experimental results show that noise-induced bias decreases the precision for the estimated parameter. Such a quantum-enhanced nonlocal polarimetry holds promise for advancing diverse fields including material science, biomedical imaging, and remote sensing, via high-precision measurements through quantum entanglement. A quantum polarimetry method using entangled photons to improve measurement precision is introduced. By calculating precision bounds and estimating the rotation angle of optical elements, both theoretically and experimentally, it is shown that the capability of entanglement to enhance accuracy is diminished with noise. Experimental noise induces bias in estimators, reducing accuracy and precision depending on chosen estimators and noise channels.