Unified toolbox for multipartite entanglement certification
Ye-Chao Liu, Jannis Halbey, Sebastian Pokutta, and Sébastien Designolle
Phys. Rev. A 114, L050401 (2026) - Published 2 November, 2026
The authors develop a conditional-gradient framework that combines rapid detection of multipartite entanglement with rigorous certification accounting for numerical errors. They demonstrate entanglement detection in systems of up to 10 qubits and use the framework to narrow the gap between entanglement and separability bounds for bound-entangled states and assess robustness under different quantum noise channels.
Tunable families of multiqubit elegant joint measurements
Jef Pauwels and Nicolas Gisin
Phys. Rev. A 114, L050402 (2026) - Published 2 November, 2026
The authors establish an explicit closed-form construction for -qubit elegant joint measurements using single-phase polynomials, showing that the measurement unitary lies at level of the Clifford hierarchy. For any even number of qubits, they also present a one-parameter family of iso-entangled, regular tetrahedral bases that smoothly connect these measurements to a 1-uniform basis.