新西兰奥塔哥大学Jevon J. Longdell团队研究了稀土掺杂反铁磁体的长光学相干时间。相关论文于2025年5月22日发表在《自然—物理学》杂志上。

稀土离子的吸收光谱具有非常窄的线宽。即使在固态晶体中，也观察到稀土离子掺杂剂的自旋和光学跃迁的相干时间非常长。主晶体中电子和核自旋的影响是限制这些相干时间的关键因素。

研究组通过在钒酸钆基质中使用铒掺杂剂来抑制电子自旋的影响，该基质完全集中在电子自旋中，但在足够低的温度下工作，使自旋形成反铁磁有序状态。他们实现了长的光学相干时间，此外，还观察到光谱中避免了交叉，这是由主体晶体中铒离子和钆磁振子之间的强耦合引起的。这表明了使用稀土离子进行磁振子介导的微波到光量子转换的可能性，这将在电信技术和在微波条件下运行的固态量子器件之间建立联系。

附：英文原文

Title: Long optical coherence times in a rare-earth-doped antiferromagnet

Author: Hiraishi, Masaya, Roberts, Zachary H., King, Gavin G. G., Trainor, Luke S., Longdell, Jevon J.

Issue&Volume: 2025-05-22

Abstract: The absorption spectra of rare-earth ions have very narrow linewidths. Even in solid-state crystals, exceedingly long coherence times have been observed for the spin and optical transitions of rare-earth-ion dopants. The influence of electronic and nuclear spins in the host crystal is a key factor limiting these coherence times. Here we suppress the effects of electron spins by using erbium dopants in a gadolinium vanadate host that is fully concentrated in electron spins but operated at sufficiently low temperatures that the spins form an antiferromagnetically ordered state. We achieve long optical coherence times and, furthermore, observe avoided crossings in the optical spectra, which are caused by strong coupling between the erbium ions and gadolinium magnons in the host crystal. This indicates the possibility of magnon-mediated microwave-to-optical quantum transduction using rare-earth ions, which would provide a connection between telecommunications technology and solid-state quantum devices operating in the microwave regime.

DOI: 10.1038/s41567-025-02920-x

Source: https://www.nature.com/articles/s41567-025-02920-x