# Variance-based uncertainty relation for incompatible observers

Variance-based uncertainty relation for incompatible observers Based on mixedness definition as $$M=1-\hbox {tr}\left( {\rho ^{2}}\right)$$ M = 1 - tr ρ 2 , we obtain a new variance-based uncertainty equality along with an inequality for Hermitian operators of a single-qubit system. The obtained uncertainty equality can be used as a measure of the system mixedness. A qubit system with feedback control is also exploited to demonstrate the new uncertainty. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Quantum Information Processing Springer Journals

# Variance-based uncertainty relation for incompatible observers

, Volume 16 (7) – May 16, 2017
10 pages

/lp/springer_journal/variance-based-uncertainty-relation-for-incompatible-observers-rZgOQqZ8Fh
Publisher
Springer US
Subject
Physics; Quantum Information Technology, Spintronics; Quantum Computing; Data Structures, Cryptology and Information Theory; Quantum Physics; Mathematical Physics
ISSN
1570-0755
eISSN
1573-1332
D.O.I.
10.1007/s11128-017-1619-6
Publisher site
See Article on Publisher Site

### Abstract

Based on mixedness definition as $$M=1-\hbox {tr}\left( {\rho ^{2}}\right)$$ M = 1 - tr ρ 2 , we obtain a new variance-based uncertainty equality along with an inequality for Hermitian operators of a single-qubit system. The obtained uncertainty equality can be used as a measure of the system mixedness. A qubit system with feedback control is also exploited to demonstrate the new uncertainty.

### Journal

Quantum Information ProcessingSpringer Journals

Published: May 16, 2017

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