Simulation of Entanglement Dynamics of Flying Qubits Through Photonic Fields

Deniz Türkpençe

Wen-Long Li, Guo‐Feng Zhang, Re-Bing Wu

The control of flying qubits is crucial for the interconnection of quantum information processing units in the future applications. Physically, this class of problems can be modeled by the radiation of optical fields from a standing qubit (natural or artificial atoms). The photon statistics of the output field emitted from a quantum system coupled to multiple waveguides is complicated when the exciton number is not conserved, especially in presence of coherent driving that is crucial for control and optimization. In this paper, we use quantum stochastic differential equation (QSDE) to describe the photon generation process, and derive the dynamical jumps induced by photon emission. Numerical simulations show that this model can be applied to analyze the manipulation process of single qubits.

Yanqiang Guo, Jie Li, Tiancai Zhang +1 more

The transfer of entanglement from optical fields to qubits provides a viable approach to entangling remote qubits in a quantum network. In cavity quantum electrodynamics, the scheme relies on the interaction between a photonic resource and two stationary intracavity atomic qubits. However, it might be hard in practice to trap two atoms simultaneously and synchronize their coupling to the cavities. To address this point, we propose and study entanglement transfer from cavities driven by an entangled external field to controlled flying qubits. We consider two exemplary non-Gaussian driving fields: NOON and entangled coherent states. We show that in the limit of long coherence time of the cavity fields, when the dynamics is approximately unitary, entanglement is transferred from the driving field to two atomic qubits that cross the cavities. On the other hand, a dissipation-dominated dynamics leads to very weakly quantum-correlated atomic systems, as witnessed by vanishing quantum discord.

Bing He, Artur Scherer

Jun‐Hong An, Shun-Jin Wang, Hong‐Gang Luo

Wang Yao, Ren‐Bao Liu, Lu Jeu Sham

We present a scheme of control for the arbitrary interplay between a stationary qubit and a flying qubit (carried by a single-photon wavepacket) at a quantum interface composed of a three-level system coupled to a continuum through a cavity. It can be used for generation or reception of an arbitrarily shaped single-photon wavepacket. The generation process can also be controlled to create entanglement between the stationary qubit and flying qubit. The generation and reception operation can be combined to perform quantum network operations such as transfer, swap and entanglement creation for qubits at distant nodes.