Abstract

We propose a systematic procedure to optimize quantum state tomography protocols for continuous variable systems based on excitation counting preceded by a displacement operation. Compared with conventional tomography based on Husimi or Wigner function measurement, the excitation counting approach can significantly reduce the number of measurement settings. We investigate both informational completeness and robustness, and provide a bound of reconstruction error involving the condition number of the sensing map. We also identify the measurement settings that optimize this error bound, and demonstrate that the improved reconstruction robustness can lead to an order-of-magnitude reduction of estimation error with given resources. This optimization procedure is general and can incorporate prior information of the unknown state to further simplify the protocol.

Publication Details
Publication Type
Journal Article
Year of Publication
2016
Volume
94
Number of Pages
052327
DOI
10.1103/PhysRevA.94.052327
URL
http://link.aps.org/doi/10.1103/PhysRevA.94.052327
Journal
Physical Review A
Contributors
Date Published
11/2016