Extracting the physical sector of quantum states

Research Projects
Organizational Units
Journal Issue
The physical nature of any quantum source guarantees the existence of an effective Hilbert space of finite dimension, the physical sector, in which its state is completely characterized with arbitrarily high accuracy. The extraction of this sector is essential for state tomography. We show that the physical sector of a state, defined in some pre-chosen basis, can be systematically retrieved with a procedure using only data collected from a set of commuting quantum measurement outcomes, with no other assumptions about the source. We demonstrate the versatility and efficiency of the physical-sector extraction by applying it to simulated and experimental data for quantum light sources, as well as quantum systems of finite dimensions.
©2017 IOP Publishing Ltd. DM acknowledges support from the National Academy of Sciences of Belarus through the program 'Convergence', the European Commission through the SUPERTWIN project (Contract No. 686731), and by FAPESP (Grant No. 2014/ 21188-0). YST acknowledges support from the BK21 Plus Program (Grant 21A20131111123) funded by the Ministry of Education (MOE, Korea) and National Research Foundation of Korea (NRF) and the KIST Institutional Program ( Project No. 2E26680-16-P025). JR. andZHacknowledge support from the Grant Agency of the Czech Republic (Grant No. 15-03194S), and the IGA Project of Palacky University (Grant No. PRF 2016-005). JT, RK, GH, and ChS acknowledge the European Commission through the QCumber project (Contract No. 665148). Finally, LLSS acknowledges the SpanishMINECO (Grant FIS2015-67963-P).