Telecom-Wavelength-Compatible Quantum Information Transcription Using Nitrogen-Vacancy Centers

TL;DR

This paper demonstrates infrared ODMR in NV centers, enabling direct, high-fidelity optical readout of spin states in the 1300-1600 nm telecom range, facilitating quantum communication integration.

Contribution

It reveals infrared ODMR as a viable, conversion-free method for reading NV center spin states in the telecom wavelength range, bridging diamond qubits and telecom infrastructure.

Findings

Infrared ODMR contrast observed at 1042 nm in NV centers.

Spin-state information transcribed to infrared emission via intersystem crossing.

Extension into 1300-1600 nm range enables direct interface with telecom systems.

Abstract

Nitrogen-vacancy (NV) centers in diamond are a leading platform for solid-state quantum sensing and quantum information processing. While most optical studies rely on the visible fluorescence associated with the triplet transitions, the infrared singlet transition near $1042$ nm, which is typically considered dark within the singlet manifold of the NV optical cycle, provides an alternative optical channel. Here, we report wavelength-resolved optically detected magnetic resonance (ODMR) measurements of this infrared emission. We directly observe ODMR contrast in the $1042$ nm emission and analyze its dependence on the magnetic field. The field-dependent spectral dispersion of the ODMR signal demonstrates that the spin-state information encoded in the NV center is transcribed to the infrared singlet emission through the spin-selective intersystem crossing, in close analogy to the visible fluorescence readout. These results establish infrared ODMR as a high-fidelity optical readout pathway. Crucially, by extending spin-state transcription directly into the $1300-1600$ nm range, this work demonstrates a direct, conversion-free interface between diamond spin-qubits and standard telecommunication infrastructure, bypassing the efficiency bottlenecks of active frequency conversion and benefiting from the already well-developed technologies in this range of the electromagnetic spectrum.