Fast quantum state transfer and entanglement preparation in strongly coupled bosonic systems

TL;DR

This paper develops analytic solutions for multi-mode bosonic systems beyond the rotating wave approximation, enabling fast, high-fidelity quantum state transfer and entanglement preparation that are robust against noise and imperfections.

Contribution

It introduces a novel scheme for quantum state transfer and entanglement creation in strongly coupled bosonic systems beyond RWA, maintaining excitation number conservation.

Findings

High-fidelity quantum state transfer achieved

Robustness against thermal noise demonstrated

Efficient preparation of Bell and W states within shortest times

Abstract

Continuous U(1) gauge symmetry, which guarantees the conservation of the total excitations in linear bosonic systems, will be broken when it comes to the strong-coupling regime where the rotation wave approximation (RWA) fails. Here we develop analytic solutions for multi-mode bosonic systems with XX-type couplings beyond RWA, and proposed a novel scheme to implement high-fidelity quantum state transfer (QST) and entanglement preparation (EP) with high speed. The scheme can be realized with designated coupling strength and pulse duration with which the excitation number keeps unchanged regardless of the breakdown of the global U(1) symmetry. In the QST tasks, we consider several typical quantum states and demonstrate that this method is robust against thermal noise and imperfections of experimental sequence. In the EP tasks, the scheme is successfully implemented for the preparation of Bell states and W-type states, within a shortest preparation time.