Please use this identifier to cite or link to this item:
|Title:||Optimal error regions for quantum state estimation|
|Source:||Shang, J., Ng, H.K., Sehrawat, A., Li, X., Englert, B.-G. (2013-12). Optimal error regions for quantum state estimation. New Journal of Physics 15 : -. ScholarBank@NUS Repository. https://doi.org/10.1088/1367-2630/15/12/123026|
|Abstract:||An estimator is a state that represents one's best guess of the actual state of the quantum system for the given data. Such estimators are points in the state space. To be statistically meaningful, they have to be endowed with error regions, the generalization of error bars beyond one dimension. As opposed to standard ad hoc constructions of error regions, we introduce the maximum-likelihood region - the region of largest likelihood among all regions of the same size - as the natural counterpart of the popular maximum-likelihood estimator. Here, the size of a region is its prior probability. A related concept is the smallest credible region - the smallest region with pre-chosen posterior probability. In both cases, the optimal error region has constant likelihood on its boundary. This surprisingly simple characterization permits concise reporting of the error regions, even in high-dimensional problems. For illustration, we identify optimal error regions for single-qubit and two-qubit states from computer-generated data that simulate incomplete tomography with few measured copies. © IOP Publishing and Deutsche Physikalische Gesellschaft.|
|Source Title:||New Journal of Physics|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Mar 29, 2018
checked on Apr 20, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.