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Published on: January 3, 2016
Measurement-induced nonlocality
Shunlong Luo1, Shuangshuang Fu
1Academy of Mathematics and Systems Science, Chinese Academy of Sciences, 100190 Beijing, People's Republic of China. luosl@amt.ac.cn
Physical Review Letters
|April 27, 2011
Summary
Measurement-induced nonlocality quantifies the global effect of local measurements. This study develops a geometric approach to measure it, providing formulas for various quantum states and discussing its implications.
Area of Science:
- Quantum Information Theory
- Quantum Measurement Theory
- Quantum Foundations
Background:
- Quantum correlations are fundamental to quantum information processing.
- Existing measures like quantum discord quantify correlations but have limitations.
- The role of local measurements in generating nonclassical effects is an active research area.
Purpose of the Study:
- To introduce and quantify measurement-induced nonlocality (MIN).
- To explore the geometric perspective of MIN.
- To derive analytical formulas for MIN in different quantum state scenarios.
Main Methods:
- Interpreting the maximum global effect of locally invariant measurements as MIN.
- Employing a geometric approach to quantify MIN.
- Deriving analytical formulas for pure states of any dimension and mixed states of 2 × n dimensions.
- Establishing a tight upper bound for MIN in general cases.
Main Results:
- A novel measure, measurement-induced nonlocality, is defined and quantified.
- Analytical formulas for MIN are obtained for various quantum states.
- A general upper bound for MIN is derived.
- MIN is shown to be dual to the geometric measure of quantum discord.
Conclusions:
- Measurement-induced nonlocality offers a new perspective on quantum correlations.
- The geometric quantification provides a powerful tool for analyzing quantum states.
- MIN has significant implications for understanding entanglement, quantumness, and secure communication.
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