2025/11/03 by Xiangjing Liu, Liu, Xiangjing, Harshit Verma +7 · 1 citation
Computer Science · Physics and Astronomy · #Channel (broadcasting) #Coherence (philosophical gambling strategy) #Density matrix #FOS: Physical sciences #Generalization #Measure (data warehouse) #Quantum #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Quantum channel #Quantum many-body systems #Quantum state #Spectroscopy and Quantum Chemical Studies #State (computer science)
paper · pdf · doi:10.48550/arxiv.2511.01179
published in arXiv (Cornell University) (Cornell University)
openalex publication_date 2025/11/03 · openalex created_date 2025/11/06 · openalex updated_date 2026/07/28
We introduce a witness-based framework for certifying quantum temporal correlations via the pseudo-density matrix (PDM) formalism, which is a spatiotemporal generalization of the density matrix. We define spatial incompatibility (SI) as the minimum distance between a PDM and valid density matrices. For trace-norm distance, we show that this reduces to the PDM's negativity, enabling the construction of experimentally accessible SI witnesses. We derive a tight bound on SI for quantum channels and analyze the respective roles of state and channel coherence in witnessing SI. Our approach, unlike the LG framework, exploits measurements that generate coherence through state disturbance. We further show that channels satisfying the LG inequality for incoherent states can still exhibit detectable SI, demonstrating that measurement disturbance enhances the certification of temporal correlations.