Qubit teleportation between non-neighbouring nodes in a quantum network

TLDR

Quantum internet applications depend on sharing quantum information across a network, and while teleportation enables reliable transfer between distant nodes, extending it beyond directly connected nodes has been limited by stringent requirements on remote entanglement, joint readout, and coherence times. This work demonstrates quantum teleportation between remote, non‑neighbouring nodes in a quantum network. The experiment uses three optically connected solid‑state spin‑qubit nodes, creating a teleporter by establishing entanglement on two links, performing entanglement swapping at the middle node, and storing the result in a memory qubit, with improvements in qubit readout, active memory protection, and tailored heralding to reduce entanglement infidelities. When the teleporter preparation is successfully heralded, arbitrary qubit states are teleported with fidelity exceeding the classical limit and unit efficiency, establishing a key building block for future multi‑node quantum network protocols.

Abstract

Abstract Future quantum internet applications will derive their power from the ability to share quantum information across the network 1,2 . Quantum teleportation allows for the reliable transfer of quantum information between distant nodes, even in the presence of highly lossy network connections 3 . Although many experimental demonstrations have been performed on different quantum network platforms 4–10 , moving beyond directly connected nodes has, so far, been hindered by the demanding requirements on the pre-shared remote entanglement, joint qubit readout and coherence times. Here we realize quantum teleportation between remote, non-neighbouring nodes in a quantum network. The network uses three optically connected nodes based on solid-state spin qubits. The teleporter is prepared by establishing remote entanglement on the two links, followed by entanglement swapping on the middle node and storage in a memory qubit. We demonstrate that, once successful preparation of the teleporter is heralded, arbitrary qubit states can be teleported with fidelity above the classical bound, even with unit efficiency. These results are enabled by key innovations in the qubit readout procedure, active memory qubit protection during entanglement generation and tailored heralding that reduces remote entanglement infidelities. Our work demonstrates a prime building block for future quantum networks and opens the door to exploring teleportation-based multi-node protocols and applications 2,11–13 .