Collapse and Revival of Entanglement between Qubits Interacting via a Quantum Bus

TL;DR

This paper investigates the dynamics of entanglement in a multi-qubit Jaynes-Cummings system, revealing a period where qubits are in attractor states independent of initial conditions, with entanglement revivals and implications for quantum information processing.

Contribution

It generalizes the concept of attractor states from one to many qubits, showing their role in entanglement dynamics and non-classicality in quantum bus interactions.

Findings

Identification of attractor states where qubits are disentangled from the field and each other.

Demonstration of entanglement collapse and subsequent revival among qubits.

Evidence that collapse and revival phenomena are generic in multi-qubit quantum bus systems.

Abstract

We study the dynamics of the Jaynes-Cummings Model for two level systems (or qubits) interacting with a quantized single mode electromagnetic cavity (or `quantum bus'). We show that there is a time in between the collapse and revival of Rabi oscillations when the state of the qubit sub-system, $| \psi\_{attractor} $, is largely independent of its initial state. This generalizes to many qubits the discovery by Gea-Banacloche for the one qubit case. The qubits in such `attractor' states are not entangled either with the field or among themselves, even if they were in the initial state. Subsequently the entanglement between the qubits revives. Finally, it is argued that the collapse and revival of entanglement and the persistence of `non-classicality' is a generic feature of multiple qubits interacting via a `quantum bus'.