Experimental demonstration of quantum overlapping tomography

Quantum tomography is one of the major challenges of large-scale quantum information research due to the exponential time complexity. In this Letter, we develop and apply a Bayesian state estimation method to experimentally demonstrate quantum overlapping tomography [Phys. Rev. Lett. 124, 100401 (2020)PRLTAO0031-900710.1103/PhysRevLett.124.100401], a scheme intent on characterizing critical information of a many-body quantum system in logarithmic time complexity. By comparing the measurement results of full-state tomography and overlapping tomography, we show that overlapping tomography gives accurate information of the system with much fewer state measurements than full-state tomography.Ministry of Education (MOE)National Research Foundation (NRF)Published versionThis research is supported by the National Research Foundation, Singapore and A*STAR under its Quantum Engineering Programme [No. NRF2021-QEP2-01-P02, No. NRF2021-QEP2-03-P01, No. 2019-0643 (QEP-P2), and No. 2019-1321 (QEP-P3)], the Singapore Ministry of Education [Grant No. MOE2016-T3-1-006 (S)]