Singlet-like correlations: equal peak work, unequal robustness

Area of Science:

• Thermodynamics
• Quantum Information Theory
• Statistical Mechanics

Background:

• System-environment correlations are recognized as a crucial thermodynamic resource.
• The erasure of these correlations enables the extraction of work.
• Understanding the behavior of these correlations under various conditions is essential for quantum thermodynamics.

Purpose of the Study:

• To compare the robustness of different correlation laws under measurement misalignment.
• To establish a hierarchy of robustness for singlet-like, rotationally covariant correlation laws.
• To investigate the operational value of classical and quantum correlations as thermodynamic resources.

Main Methods:

• Comparison of three correlation laws: a local classical benchmark, the quantum cosine law, and a stronger-than-quantum step law.
• Analysis under conditions of measurement misalignment.
• Focus on the binary-outcome, uniform-marginal setting.

Main Results:

• All three correlation laws can achieve the same peak extractable work ($k_{B}Tln2$) in the ideal case.
• The quantum cosine law exhibits greater robustness to measurement misalignment than the classical benchmark.
• The stronger-than-quantum step law shows remarkable robustness, remaining unaffected until a critical angle.

Conclusions:

• Quantum correlations offer enhanced robustness as a thermodynamic resource compared to classical correlations.
• A hierarchy of robustness exists among these correlation laws, with quantum laws generally outperforming classical ones.
• The study clarifies the practical utility of different correlation types in real-world, imperfect measurement scenarios.