Quantum teleportation between remote atomic-ensemble quantum memories

TLDR

Quantum teleportation and quantum memory are essential for large‑scale quantum networks, enabling faithful state transfer between distant nodes via entanglement and controlled storage of photonic qubits in stationary matter systems. The study demonstrates quantum teleportation between two remote atomic‑ensemble quantum memory nodes, each with ~10^8 rubidium atoms linked by a 150‑m fiber. The protocol maps the spin‑wave state of one ensemble to a photon, performs a Bell‑state measurement with a photon entangled to the other ensemble’s spin wave, and uses a 150‑m fiber link. Teleportation succeeded with 88(7)% fidelity, and the method could enable quantum information transfer between network nodes and distributed quantum computing. Bennett et al.

Abstract

Quantum teleportation and quantum memory are two crucial elements for large-scale quantum networks. With the help of prior distributed entanglement as a “quantum channel,” quantum teleportation provides an intriguing means to faithfully transfer quantum states among distant locations without actual transmission of the physical carriers [Bennett CH, et al. (1993) Phys Rev Lett 70(13):1895–1899]. Quantum memory enables controlled storage and retrieval of fast-flying photonic quantum bits with stationary matter systems, which is essential to achieve the scalability required for large-scale quantum networks. Combining these two capabilities, here we realize quantum teleportation between two remote atomic-ensemble quantum memory nodes, each composed of ∼10 8 rubidium atoms and connected by a 150-m optical fiber. The spin wave state of one atomic ensemble is mapped to a propagating photon and subjected to Bell state measurements with another single photon that is entangled with the spin wave state of the other ensemble. Two-photon detection events herald the success of teleportation with an average fidelity of 88(7)%. Besides its fundamental interest as a teleportation between two remote macroscopic objects, our technique may be useful for quantum information transfer between different nodes in quantum networks and distributed quantum computing.