Genuine $k$-partite correlations and entanglement in the ground state of the Dicke model for interacting qubits

Antônio C. Lourenço, Denis R. Candido, Eduardo I. Duzzioni

Published 2024-05-21Version 1

The analysis of correlations among subsystems is essential for both the understanding of critical phenomena and for performing quantum information tasks. However, the majority of correlation measures are restricted to bipartitions due to the inherent challenges associated with handling multiple partitions and subsystems. To address this, we investigate Genuine Multipartite Correlations (GMC) of the Dicke model with interacting qubits. This method allows for the precise quantification of correlations within each subpart of the system, as well as for the percentage contribution of each GMC of order $k$. Most importantly, we show that GMC signal both first- and second-order quantum phase transitions present in the model. Furthermore, we employ Quantum Fisher Information (QFI) to detect genuine multipartite entanglement, since the GMC encompass both classical and quantum correlations. Ultimately, we compare the Dicke model with interacting qubits to spin-centers in solids interacting with a quantum field of magnons to demonstrate a potential experimental realization of this generalized Dicke model.