Quantum synchronization with correlated baths

We study quantum synchronization under the nonequilibrium reservoirs.We consider a two-qubit XXZ chain coupled independently to their own reservoirs modeled by the collisional model.Two reservoir particles,initially prepared in a thermal state or a state with coherence,are correlated through a unitary transformation and afterward interact locally with the two quantum subsystems.We study the quantum effect of reservoir on synchronous dynamics of system.By preparing different reservoir initial states or manipulating the reservoir particles coupling and the temperature gradient,we find that quantum entanglement of reservoir is the key to control quantum synchronization of system qubits.

A scheme for implementing quantum clock synchronization algorithm in cavity QED

In this paper, we propose a scheme for implementing the quantum clock synchronization （QCS） algorithm in cavity quantum electrodynamic （QED） formalism. Our method is based on three-level lader-type atoms interacting with classical and quantized cavity fields. Atom-qubit realizations of three-qubit and four-qubit QCS algorithms are explicitly presented.

Measure synchronization in hybrid quantum-classical systems

Measure synchronization in hybrid quantum-classical systems is investigated in this paper.The dynamics of the classical subsystem is described by the Hamiltonian equations,while the dynamics of the quantum subsystem is governed by the Schr¨odinger equation.By increasing the coupling strength in between the quantum and classical subsystems,we reveal the existence of measure synchronization in coupled quantum-classical dynamics under energy conservation for the hybrid systems.

Effects of Quantum Noise on Quantum Clock Synchronization

In laboratory environment, the channel apparatus will generate particular dominant quantum noise. The noise then will give rise to some errors during synchronization. In this work, the accuracies of one qubit transport protocol and entangled states transport protocol in the presence of noise have been studied. With the help of three important and familiar noise models, the quantum noise will degrade the accuracy has been proved. Due to the influence of quantum noise, the accuracy of entangled qubits decrease faster than that of one qubit. The entangled states will improve the accuracy in noise-free channel, and will degrade the accuracy in noise channel.

Effect of non-Markovianity on synchronization

We investigate the transient spontaneous quantum synchronization between two qubits interacting with a common non-Markovian environment based on a collision model.We are mainly interested in the effect of non-Markovianity on the synchronization between two qubits.We find that the non-Markovianity always delay the anti-synchronization and decrease the parameter region where the qubits get anti-synchronized.Meanwhile,we define V to characterize the visibility of synchronization and show that there is an apparent link among V,entanglement and quantum mutual information whether in the Markovian or non-Markovian regimes when the environment is in the vacuum state.Moreover,with the increase of temperature,the parameter region of the emergence of anti-synchronization and the time to get anti-synchronized in the non-Markovian regime gradually approaches that in the Markovian regime.The high temperature decreases the parameter region of the emergence of anti-synchronization in both Markovian and non-Markovian regimes,and breaks the connection among V,entanglement and quantum mutual information.

Accuracy for superposition of squeezed states in lossless and dissipative channel

The analysis of accuracy for superposition of squeezed states （SSSs） in lossless and loss case has been performed in this study. In lossless case, time accuracies of SSSs with mean photon number ns have a scaling of ns-2 in two limits of large and small squeezing. With the help of photon loss model, the dissipative channel will degrade accuracies has been proved. In the limit of large squeezing, the accuracy will slowly decrease with the reduction of transmittance η. In the limit of small squeezing, time accuracy scales as 1/（η4n2） and will decrease much faster along with η decreases.