2017/11/14 by Kuan Zhang, Jiajun Ma, Xiang Zhang +4 · 4 citations
Computer Science · Mathematics · Physics and Astronomy · #Antipodal point #Condensed matter physics #Controlled NOT gate #Mathematics #Physics #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum gate #Quantum information #Quantum information processing #Quantum mechanics #Quantum optics and atomic interactions #Spins #Unitary state #physics.atom-ph #quant-ph
paper · pdf · doi:10.1016/j.scib.2018.05.011
published in 中国科学通报：英文版 63(12), 765-770 · 17 pages, 6 figures
arxiv created 2017/11/14 · openalex publication_date 2018/05/17 · arxiv updated 2019/02/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The NOT gate that flips a classical bit is ubiquitous in classical information processing. However its quantum analogue, the universal NOT (UNOT) gate that flips a quantum spin in any alignment into its antipodal counterpart is strictly forbidden. Here we explore the connection between this discrepancy and how UNOT gates affect classical and quantum correlations. We show that while a UNOT gate always preserves classical correlations between two spins, it can non-locally increase or decrease their shared discord in ways that allow violation of the data processing inequality. We experimentally illustrate this using a multi-level trapped \Yb ion that allows simulation of anti-unitary operations.