2018年4月1日
Solid-state electron spin lifetime limited by phononic vacuum modes
Nature Materials
- 巻
- 17
- 号
- 4
- 開始ページ
- 313
- 終了ページ
- 317
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1038/s41563-017-0008-y
- 出版者・発行元
- Nature Publishing Group
Longitudinal relaxation is the process by which an excited spin ensemble decays into its thermal equilibrium with the environment. In solid-state spin systems, relaxation into the phonon bath usually dominates over the coupling to the electromagnetic vacuum 1-9 . In the quantum limit, the spin lifetime is determined by phononic vacuum fluctuations 10 . However, this limit was not observed in previous studies due to thermal phonon contributions 11-13 or phonon-bottleneck processes 10, 14,15 . Here we use a dispersive detection scheme 16,17 based on cavity quantum electrodynamics 18-21 to observe this quantum limit of spin relaxation of the negatively charged nitrogen vacancy (NV-) centre 22 in diamond. Diamond possesses high thermal conductivity even at low temperatures 23, which eliminates phonon-bottleneck processes. We observe exceptionally long longitudinal relaxation times T 1 of up to 8 h. To understand the fundamental mechanism of spin-phonon coupling in this system we develop a theoretical model and calculate the relaxation time ab initio. The calculations confirm that the low phononic density of states at the NV- transition frequency enables the spin polarization to survive over macroscopic timescales.
- ID情報
-
- DOI : 10.1038/s41563-017-0008-y
- ISSN : 1476-4660
- ISSN : 1476-1122
- SCOPUS ID : 85041929312