PPT-preserving operations

What computable expression, if any, equals the regularized exact PPT distillable entanglement of a bipartite state?

• Quantum Resource Theory
• Entanglement distillation
• PPT-preserving operations
• Additivity and regularization
• One-shot and finite-blocklength bounds

Is the Rains bound asymptotically achievable by completely positive-partial-transpose-preserving (completely PPT-preserving) channels for every full-rank two-qubit Bell-diagonal state, and what channel family achieves it?

• Quantum Resource Theory
• Entanglement distillation
• PPT-preserving operations
• Bell-diagonal states

Does the semidefinite hierarchy for exact PPT entanglement cost collapse at its second level for every finite-dimensional bipartite density operator \(\rho_{AB}\)?

• Quantum Resource Theory
• Entanglement cost
• PPT-preserving operations
• Entanglement measures