2019/01/23 by Timo Simnacher, Nikolai Wyderka, René Schwonnek +1
Computer Science · Physics and Astronomy · #Algorithm #Computer science #Entropy (arrow of time) #Invariant (physics) #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum entanglement #Quantum mechanics #Qubit #Scrambling #Set (abstract data type) #Statistical Mechanics and Entropy #Statistical physics #quant-ph
paper · pdf · doi:10.1103/physreva.99.062339
published as Phys. Rev. A 99, 062339 (2019) · 9 pages, 6 figures
arxiv created 2019/01/23 · openalex publication_date 2019/06/27 · arxiv updated 2019/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
In the usual entanglement detection scenario the possible measurements and the corresponding data are assumed to be fully characterized. We consider the situation where the measurements are known, but the data is scrambled, meaning the assignment of the probabilities to the measurement outcomes is unknown. We investigate in detail the two-qubit scenario with local measurements in two mutually unbiased bases. First, we discuss the use of entropies to detect entanglement from scrambled data, showing that Tsallis and R'enyi entropies can detect entanglement in our scenario, while the Shannon entropy cannot. Then, we introduce and discuss scrambling-invariant families of entanglement witnesses. Finally, we show that the set of nondetectable states in our scenario is nonconvex and therefore in general hard to characterize.