近日，清华大学的孙洪波&林琳涵及其研究团队取得一项新进展。经过不懈努力，他们通过波导辅助能量量子转移实现可调谐的单发射腔耦合强度。相关研究成果已于2024年7月18日在国际知名学术期刊《光：科学与应用》上发表。

该研究团队提出一种称为波导辅助能量量子转移(WEQT)的策略，通过扩大相互作用截面来提高单发射腔耦合强度。多个辅助发射器通过波导光学连接，提供间接耦合通道在目标发射器和腔之间传递能量量子。耦合强度的显著增强，其增强系数达到{g}/g > 10，极大地放宽了对空腔设计的严格要求。

作为这一概念的深入拓展，研究人员还成功验证了该辅助比特可作为光子门的控制比特，为量子操纵开辟了新的自由度。

据悉，发射腔强耦合对量子技术的开发具有重要意义，特别是在单个发射腔的尺度上。然而，由于光-物质相互作用截面小，单发射腔强耦合对腔的质量因子和光子态的局部密度要求苛刻，因此受到了限制。

附：英文原文

Title: Tunable single emitter-cavity coupling strength through waveguide-assisted energy quantum transfer

Author: Liu, Yuan, Zhou, Hongwei, Lin, Linhan, Sun, Hong-Bo

Issue&Volume: 2024-07-18

Abstract: The emitter-cavity strong coupling manifests crucial significance for exploiting quantum technology, especially in the scale of individual emitters. However, due to the small light-matter interaction cross-section, the single emitter-cavity strong coupling has been limited by its harsh requirement on the quality factor of the cavity and the local density of optical states. Herein, we present a strategy termed waveguide-assisted energy quantum transfer (WEQT) to improve the single emitter-cavity coupling strength by extending the interaction cross-section. Multiple ancillary emitters are optically linked by a waveguide, providing an indirect coupling channel to transfer the energy quantum between target emitter and cavity. An enhancement factor of coupling strength widetilde{g}/g > 10 can be easily achieved, which dramatically release the rigorous design of cavity. As an extension of concept, we further show that the ancillae can be used as controlling bits for a photon gate, opening up new degrees of freedom in quantum manipulation.

DOI: 10.1038/s41377-024-01508-z

Source: https://www.nature.com/articles/s41377-024-01508-z