Controllable coupling and quantum correlation dynamics of two double quantum dots coupled via a transmission line resonator

TL;DR

This paper presents a theoretical scheme for controlling quantum correlations between two double quantum dot spin qubits via a transmission line resonator, revealing synchronization phenomena and controllable stationary states.

Contribution

It introduces a method to generate and control quantum correlations and their dynamics in coupled quantum dot systems using a transmission line resonator.

Findings

Existence of stationary discord states with controllable amplification or degradation.

Synchronization and anti-synchronization phenomena in quantum correlation dynamics.

Quantum correlations can be manipulated by initial states, coupling strength, and detuning.

Abstract

We propose a theoretical scheme to generate a controllable and switchable coupling between two double-quantum-dot (DQD) spin qubits by using a transmission line resonator (TLR) as a bus system. We study dynamical behaviors of quantum correlations described by entanglement correlation (EC) and discord correlation (DC) between two DQD spin qubits when the two spin qubits and the TLR are initially prepared in $X$-type quantum states and a coherent state, respectively. We demonstrate that in the EC death regions there exist DC stationary states in which the stable DC amplification or degradation can be generated during the dynamical evolution. It is shown that these DC stationary states can be controlled by initial-state parameters, the coupling, and detuning between qubits and the TLR. We reveal the full synchronization and anti-synchronization phenomena in the EC and DC time evolution, and show that the EC and DC synchronization and anti-synchronization depends on the initial-state parameters of the two DQD spin qubits. These results shed new light on dynamics of quantum correlations.