https://doi.org/10.1140/epjc/s10052-024-12855-x
Regular Article - Theoretical Physics
Notes on time entanglement and pseudo-entropy
Chennai Mathematical Institute, H1 SIPCOT IT Park, 603103, Siruseri, India
Received:
22
January
2024
Accepted:
26
April
2024
Published online:
14
May
2024
Following arXiv:2210.12963 [hep-th], we investigate aspects of the time evolution operator regarded as a density operator and associated entanglement-like structures in various quantum systems. These involve timelike separations and generically lead to complex-valued entropy, although there are interesting real subfamilies. There are many parallels and close relations with reduced transition matrices and pseudo-entropy, which we discuss and clarify. For instance, a related quantity involves the time evolution operator along with a projection onto some initial state, which amounts to analysing pseudo-entropy for the initial state and its time-evolved final state.
© The Author(s) 2024
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