Hadron Structure by Quantum Computing

This paper reviews two methods for studying the hadron partonic structure by quantum computing: (1) Direct calculation of parton distribution functions (PDFs) through light-cone correlators; (2) Based on QCD factorization theorem, extract PDFs from hadronic tensors which are calculated on a quantum computer. Based on the methodology of the second method and the quantum algorithm developed in reference(LI T, GUO X, LAI W K, et al. Phys Rev D, 2022, 105(11): L111502), we proposed a quantum algorithm for calculating hadronic tensors. To verify the effectiveness of our quantum algorithm, we computed the hadronic tensor of the Schwinger model and found that the results from quantum computing match those from exact diagonalization obtained by classical simulation. Finally, we briefly discuss the quantum computing resources required for calculating PDFs using the second method mentioned above.