Quantum teleportation and quantum information processing

Akira Furusawa, Timothy C. Ralph, Ping Koy Lam

Masahiro Takeoka, Masahide Sasaki

Akira Furusawa, Nobuyuki Takei

Shuyan Zhou, Pengfei Zhang, Yu Zf

Quantum teleportation is a phenomenon arising from entanglement, decisively distinguishing the classical and quantum worlds. The recent success of many-body quantum teleportation is even more surprising: Although input information is initially dispersed and encoded into the many-body state in a complex way, the teleportation process can refocus this highly nonlocal information at the receiver's end. This success manifests intriguing capability of many-body systems in quantum information processing. Current studies indicate that information scrambling, a generic dynamic process in many-body systems, underlies the effectiveness of many-body quantum teleportation. However, this process is known to undergo a scrambling-dissipation transition in the presence of environments. How environments affect the quantum information processing capability of many-body systems calls for further investigation. In this work, we study many-body quantum teleportation in the presence of environments. We predict two emergent critical points that hallmark the transitions of the teleportation performance from the quantum regime to the classical regime and finally to the no-signal regime as the system-environment coupling, quantified by γ , increases. In the quantum regime, teleportation can outperform its classical counterparts, while in the classical regime, it can be replaced by a classical channel. Our prediction is based on a generic argument harnessing the relationship between many-body quantum teleportation and information scrambling, corroborated by solvable Brownian Sachdev-Ye-Kitaev models.

Hidehiro Yonezawa

Quantum teleportation is one of the most fundamental subjects in quantum information technology. This is because quantum teleportation can be used as not only a communication network but also a building block for universal quantum information processing. It is well known that there are two approaches (i. e. discrete and continuous variable approaches) in quantum information processing. In particular, continuous variable one has some advantages, that is, capability for deterministic and efficient quantum operations. In the case of continuous variable quantum teleportation, however, we cannot teleport quantum states perfectly due to finite level of quadrature squeezed states. Hence it is important to improve the fidelity of teleportation to realize more advanced quantum network and circuits. Thanks to the recent improvement of squeezing level, fidelity up to F=0.83 has been achieved. In this article, we review the experiment of high fidelity quantum teleportation for continuous variables, and its applications.

Andrew Whitaker