Robustness measures for quantifying nonlocality
Year: 2025
Type: article
Abstract: We suggest generalized robustness for quantifying nonlocality and derive its equivalence to the maximum violation ratio of Bell inequalities defined as vectors with non-negative elements. We investigate its properties by comparing it with white-noise and standard robustness measures. As a result, we show that white-noise robustness does not fulfill monotonicity under local operations and shared randomness, whereas the other measures do. To compare the standard and generalized robustness measures, we introduce the concept of inequivalence, which indicates a reversal in the order relationship depending on the choice of monotones. From an operational perspective, the inequivalence of monotones for resourceful objects implies the absence of free operations that connect them. Applying this concept, we find that standard and generalized robustness measures are inequivalent between even- and odd-dimensional cases up to eight dimensions. This is obtained using randomly performed Collins–Gisin–Linden–Massar–Popescu measurement settings in a maximally entangled state. This study contributes to the resource theory of nonlocality and sheds light on comparing monotones by using the concept of inequivalence valid for all resource theories.
Source: New Journal of Physics
Authors: Kyunghyun Baek, Junghee Ryu, Jinhyoung Lee
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,610
Funders: National Research Foundation, Ministry of Science, ICT and Future Planning, Korea Institute of Science and Technology, Korea Institute of Science and Technology Information, National Research Foundation of Korea, Iran Telecommunication Research Center, Ministry of Science and ICT, South Korea
OpenAlex ID: W4409500280