Photon-assisted Landau Zener transitions in a tunable driven Rabi dimer coupled to a micromechanical resonator

TL;DR

This paper investigates how photons and phonons influence Landau-Zener transitions and qubit control in a tunable, driven Rabi dimer system with a micromechanical resonator, using advanced variational methods.

Contribution

It introduces a detailed analysis of photon-assisted Landau-Zener transitions in a hybrid Rabi dimer coupled to a phonon mode, revealing the roles of phonon frequency and coupling strength.

Findings

Low phonon frequencies can alter qubit dynamics.

Strong phonon coupling significantly perturbs qubit behavior.

Photon frequency influences qubit oscillation frequency.

Abstract

Employing the multiple Davydov D$_2$ Ansatz with the time-dependent variational principle, we have investigated photon-assisted Landau-Zener (LZ) transitions and qubit manipulation in a hybrid quantum electrodynamics device. Modelled as a Rabi dimer, the device comprises of two interacting transmission-line resonators, each coupled to a qubit. The qubits, driven by independent harmonic fields, are further modulated by a micromechanical resonator mimicked by a phonon mode. The impacts of two independent driving fields on the qubit dynamics are carefully examined. The energy diagram of the system and the photon number mobilization on the resonators are analyzed to explain the behaviour of the LZ transitions and qubit dynamics while taking into account the influence of the single phonon mode. Results show that low phonon frequencies can alter the qubit dynamics, particularly in the absence of the driving fields, {and a strong phonon coupling strength can significantly perturb the qubit dynamics thanks to a high influx of phonon energy}. Notably, only the photon frequency affects the oscillation frequency of qubit polarization. This study unveils the imperative roles that photons and phonons play in the Rabi dimer model.