NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PUBLICATIONS

Joint Quantum State and Measurement Tomography with Incomplete Measurements

Published

Author(s)

Adam C. Keith, Charles H. Baldwin, Scott C. Glancy, Emanuel H. Knill

Abstract

Estimation of quantum states and measurements is crucial for the implementation of quantum information protocols. The standard method for each is quantum tomography (QT). However, QT suffers from systematic errors caused by imperfect knowledge of the system. We present a procedure to simultaneously characterize quantum states and measurements that mitigates systematic errors by use of a single high-fidelity state preparation and a limited set of high- fidelity unitary operations. Such states and operations are typical of many state-of-the-art systems. We design a set of experiments for the situation in question and use alternating maximum likelihood iterations to estimate measurement operators and unknown quantum states from the data. In some cases, the procedure does not enable unique estimation of the states. For these cases, we show how one may identify a set of density matrices compatible with the measurements and use a semi-definite program to place bounds on the state's expectation values. We demonstrate the procedure on data from a simulated experiment with two trapped ions.
Citation
Physical Review A
Volume
98
Issue
4
Pub Type
Journals

Download Paper

https://doi.org/10.1103/PhysRevA.98.042318

Keywords

quantum information, quantum tomography, ion trapping, maximum likelihood, statistics
Statistical analysis, Uncertainty quantification and Quantum information science

Citation

Keith, A. , Baldwin, C. , Glancy, S. and Knill, E. (2018), Joint Quantum State and Measurement Tomography with Incomplete Measurements, Physical Review A, [online], https://doi.org/10.1103/PhysRevA.98.042318 (Accessed October 10, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created October 12, 2018, Updated November 10, 2018
Was this page helpful?