Resource-efficient fault-tolerant one-way quantum repeater with code concatenation

TL;DR

This paper introduces a resource-efficient one-way quantum repeater design using code concatenation, enabling long-distance quantum communication with minimal qubit resources and operational complexity.

Contribution

It proposes a novel repeater architecture combining tree-cluster and 5-qubit codes with flag-based stabilizer measurements for efficient error correction.

Findings

Intercontinental distances up to 10,000 km are achievable.

Resource overhead is minimized by specialized repeater nodes.

The approach significantly reduces experimental requirements for quantum communication.

Abstract

One-way quantum repeaters where loss and operational errors are counteracted by quantum error correcting codes can ensure fast and reliable qubit transmission in quantum networks. It is crucial that the resource requirements of such repeaters, for example, the number of qubits per repeater node and the complexity of the quantum error correcting operations are kept to a minimum to allow for near-future implementations. To this end, we propose a one-way quantum repeater that targets both the loss and operational error rates in a communication channel in a resource-efficient manner using code concatenation. Specifically, we consider a tree-cluster code as an inner loss-tolerant code concatenated with an outer 5-qubit code for protection against Pauli errors. Adopting flag-based stabilizer measurements, we show that intercontinental distances of up to 10,000 km can be bridged with a minimal resource overhead by interspersing repeater nodes that each specializes in suppressing either loss or operational errors. Our work demonstrates how tailored error-correcting codes can significantly lower the experimental requirements for long-distance quantum communication.