Internal Entanglement and External Correlations of Any Form Limit Each Other

Area of Science:

• Quantum Information Science
• Quantum Mechanics
• Quantum Correlation Studies

Background:

• Entanglement and correlations are fundamental concepts in quantum mechanics.
• Understanding the interplay between different types of correlations is key to advancing quantum information processing.

Purpose of the Study:

• To establish a direct relationship between quantum entanglement and all forms of correlations.
• To investigate how external correlations influence internal entanglement in bipartite quantum systems.

Main Methods:

• Analysis of the relationship between internal entanglement and external correlations.
• Utilizing measures of correlation such as entanglement monotones, mutual information, and classical correlations.
• Examining the behavior of these measures under local operations.

Main Results:

• A fundamental limit exists between a bipartite system's internal entanglement and its external correlations.
• Measures of correlation, regardless of type, are invariant under local operations.
• External correlations impose a strict upper bound on internal entanglement, which decreases as external correlations increase.

Conclusions:

• The study reveals a trade-off relationship between entanglement and correlations.
• Quantum discord and internal entanglement are shown to decrease with increasing external correlations.
• This finding has implications for quantifying and manipulating quantum correlations.