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Horodeckis: explicit PPT-entangled states and undistillable bound entanglement

Contribution grade

Quantum information and entanglement distillation · Exact theorem and reusable mathematical method

Reference score250,000Provisional editorial estimate of this exact contribution; its grade is assessed separately.

What changed

Paweł Horodecki constructed explicit entangled states with positive partial transpose in 3x3 and 2x4 dimensions using a range criterion. The 1998 Horodecki paper proves that distillability requires a negative partial transpose: PPT states remain PPT under tensor powers and local operations with classical communication, hence these entangled states cannot be distilled into singlets.

Scientific scope

Paweł Horodecki constructed explicit entangled states with positive partial transpose in 3x3 and 2x4 dimensions using a range criterion. The 1998 Horodecki paper proves that distillability requires a negative partial transpose: PPT states remain PPT under tensor powers and local operations with classical communication, hence these entangled states cannot be distilled into singlets. The 1997 construction has a sole-author byline; the 1998 nondistillability theorem has three authors. The converse that every NPT state is distillable is not proved. Bound entanglement here means no singlet distillation under the specified operations, not no possible use in every communication, privacy or activation task.

Evidence

The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. The 1997 construction has a sole-author byline; the 1998 nondistillability theorem has three authors. The converse that every NPT state is distillable is not proved. Bound entanglement here means no singlet distillation under the specified operations, not no possible use in every communication, privacy or activation task.

Contributors

Provisional WRS assessment, edition 2026-10-23.9. Independent expert calibration is pending. This grade does not certify correctness or assign ownership.

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