# Exact Entanglement dynamics in Three Interacting Qubits

## TL;DR

This paper analytically investigates the entanglement entropy transfer in three interacting qubits, revealing how entanglement dynamically shifts among pairs and can generate genuine three-partite entanglement, with implications for experimental tests.

## Contribution

It provides an exact analytical study of entanglement dynamics in three qubits, including the transfer mechanisms and conditions for genuine tripartite entanglement.

## Key findings

- Entanglement entropy can transfer between qubit pairs dynamically.
- Different interaction symmetries lead to symmetric or asymmetric entanglement evolution.
- Proposes an experimental setup with Rydberg atoms to observe these effects.

## Abstract

Motivated by recent experimental study on coherent dynamics transfer in three interacting atoms or electron spins \cite{Barredo:2015,Rosenfeld:2018}, here we study entanglement entropy transfer in three interacting qubits. We analytically calculate time evolutions of wave function, density matrix and entanglement of the system. We find that initially entangled two qubits may alternatively transfer their entanglement entropy to other two qubit pairs. So that dynamical evolution of three interacting qubits may produce a genuine three-partite entangled state through entanglement entropy transfers. In particular, different pairwise interactions of the three qubits endow symmetric and asymmetric evolutions of the entanglement transfer, characterized by the quantum mutual information and concurence. Finally, we discuss an experimental proposal of three Rydberg atoms for testing the entanglement dynamics transfer of this kind.