Work

Entanglement in the symmetric subspace: Mapping multipartite to bipartite states

Year: 2026

Type: article

Abstract: We propose a technique to investigate multipartite entanglement in the symmetric subspace. Our approach is to map an N -qubit symmetric state onto a bipartite symmetric state of higher local dimension. We show that this mapping preserves separability and allows to characterize the entanglement of the original multipartite state. In particular, we establish a connection between the border rank and the Schmidt rank, and derive lower bounds on entanglement measures. Finally, we reveal the existence of entangled symmetric subspaces, where all bipartite states are entangled.

Source: APS Open Science

DOI: 10.1103/6g5t-hlsr

Authors: Carlo Marconi, Satoya Imai

Institutions: National Research Council, University of Tsukuba

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: hybrid

Funders: European Commission, Japan Science and Technology Corporation, HORIZON EUROPE Framework Programme