Year: 2025
Type: article
Abstract: We construct linear and nonlinear entanglement witnesses, by tensoring and partial tracing existing states and witnesses. We show that little shared quantum resources allow one to employ decomposable witnesses to obtain larger ones detecting locally undistillable states and find analytic witnesses for multipartite entangled states that are undistillable across all bipartitions. Crucially, we show how to efficiently optimize multicopy witnesses to desired states, which is a current challenge. As an example of both theoretical and experimental interest, existing trace polynomial witnesses are significantly improved while preserving their symmetries and implementability with randomized measurements. In addition to detecting entanglement, we also find new witnesses detecting k-copy distillability. A recipe for the single-copy case is shown to be effective for generic and Werner states.
Source: Physical Review Letters
DOI: 10.1103/d6q5-k7sh
Author: Albert Rico
Institutions: Universitat Autònoma de Barcelona, Jagiellonian University
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4415397358