Laser Physics Letters
Quantum-state texture of assistance via the trace distance and Bures measures
Wenhua Wang, Zhengli Chen
Abstract
Abstract Quantum-state texture has recently been recognized as a legitimate quantum resource, attracting increasing attention alongside the development of quantum theory. In this work, we investigate quantifications of the quantum-state texture of assistance based on the trace distance and Bures measures, which characterize the maximum possible average texture over all pure-state decompositions of a given quantum state. We show that both quantities are bounded and concave, the former is monotonic, whereas the latter is not. Notably, we derive the closed-form expressions for these two quantities. Furthermore, we establish global-versus-marginal bounds for them for any bipartite state. Both quantities satisfy subadditivity, and for product states, the global and partial quantities are each related by an equality.