Efficient steady state entanglement generation in strongly driven coupled qubits

TL;DR

This paper presents a method to efficiently generate and control steady-state entanglement in coupled qubits driven strongly by microwaves, leveraging Landau-Zener-Stückelberg processes and reservoir tuning.

Contribution

It introduces a novel entanglement generation mechanism that does not require fine-tuning of multiphoton resonances, depending instead on qubit-qubit coupling sign and system design.

Findings

Maximal entanglement (concurrence close to 1) achievable over wide driving ranges

Entanglement controlled by qubit-reservoir coupling tuning

Mechanism effective without precise multiphoton resonance tuning

Abstract

We report on a mechanism to optimize the generation of steady-state entanglement in a system of coupled qubits driven by microwave fields. Due to the interplay between Landau-Zener-St\"uckerlberg pumping involving three levels and a subsequent fast relaxation channel, which is activated by tuning the qubits-reservoir couplings, a maximally entangled state can be populated. This mechanism does not require from the fine-tuning of multiphoton-resonances but depends on the sign of the qubit-qubit coupling. In particular, we find that by a proper design of the system parameters and the driving protocol, the two-qubits steady-state concurrence can attain values close to 1 in a wide range of driving amplitudes. Our results may be useful to gain further insight into entanglement control and manipulation in dissipative quantum systems exposed to strong driving.