Robust transfer of a quantum state from an absorbed photon into a diamond spin

TL;DR

This paper demonstrates a robust quantum state transfer from a photon to a diamond spin using teleportation, achieving high fidelity despite spectral and temporal errors, which advances quantum networking capabilities.

Contribution

The authors experimentally realize a teleportation-based quantum state transfer method that is resilient to spectral and temporal misalignments, improving robustness over traditional approaches.

Findings

Fidelity exceeds 0.94 with 100 MHz spectral error

Fidelity exceeds 0.93 with 100 ns timing error

Enables robust entanglement between remote quantum memories

Abstract

Conversion of a quantum state from a flying qubit to a memory qubit is crucial for distributed quantum computing. However, this requires precise spatiotemporal or frequency/phase alignment. Here, we experimentally demonstrate quantum teleportation-based state transfer from a photon into a spin in a nitrogen-vacancy center in diamond robust against both spectral and temporal errors. The achieved fidelity exceeds 0.94 within a frequency error of 100 MHz and 0.93 within an arrival-time error of 100 ns. This achievement enables extraordinarily robust entanglement generation between remote quantum memories compared with the conventional photon-interference-based approaches and paves the way for stable quantum networks.