Journal
NPJ QUANTUM INFORMATION
Volume 2, Issue -, Pages -Publisher
NATURE PUBLISHING GROUP
DOI: 10.1038/npjqi.2016.1
Keywords
-
Categories
Funding
- National Fundamental Research Program [2011CBA00200, 2011CB9211200]
- National Natural Science Foundation of China [61108009, 61222504, 11574291]
- Perimeter Institute for Theoretical Physics
- Government of Canada through Industry Canada
- Province of Ontario through the Ministry of Research and Innovation
- Excellence Initiative of the German Federal and State Governments [ZUK 81]
- DFG
Ask authors/readers for more resources
The precision limit in quantum state tomography is of great interest not only to practical applications but also to foundational studies. However, little is known about this subject in the multiparameter setting even theoretically due to the subtle information trade-off among incompatible observables. In the case of a qubit, the theoretic precision limit was determined by Hayashi as well as Gill and Massar, but attaining the precision limit in experiments has remained a challenging task. Here we report the first experiment that achieves this precision limit in adaptive quantum state tomography on optical polarisation qubits. The two-step adaptive strategy used in our experiment is very easy to implement in practice. Yet it is surprisingly powerful in optimising most figures of merit of practical interest. Our study may have significant implications for multiparameter quantum estimation problems, such as quantum metrology. Meanwhile, it may promote our understanding about the complementarity principle and uncertainty relations from the information theoretic perspective.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available