Affiliation:
1. Institute of Nanotechnology (INT) Karlsruhe Institute of Technology (KIT) Kaiserstraße 12 76131 Karlsruhe Germany
2. Institute of Quantum Materials and Technologies (IQMT) Karlsruhe Institute of Technology (KIT) Kaiserstraße 12 76131 Karlsruhe Germany
3. Physikalisches Institut (PHI) Karlsruhe Institute of Technology (KIT) Kaiserstraße 12 76131 Karlsruhe Germany
4. Karlsruhe Nano Micro Facility (KNMFi) Karlsruhe Institute of Technology (KIT) Kaiserstraße 12 76131 Karlsruhe Germany
5. Centre Européen de Sciences Quantiques (CESQ) Institut de Science et d'Ingénierie Supramoléculaires (ISIS) 8 allée Gaspard Monge, BP 70028 67083 Strasbourg Cedex France
Abstract
AbstractCoordination complexes of rare‐earth ions (REI) show optical transitions with narrow linewidths enabling the creation of coherent light‐matter interfaces for quantum information processing (QIP) applications. Among the REI‐based complexes, Eu(III) complexes showing the 5D0→7F0 transition are of interest for QIP applications due to the narrow linewidths associated with the transition. Herein, we report on the synthesis, structure, and optical properties of a novel Eu(III) complex and its Gd(III) analogue composed of 2,9‐bis(pyrazol‐1‐yl)‐1,10‐phenanthroline (dpphen) and three nitrate (NO3) ligands. The Eu(III) complex—[Eu(dpphen)(NO3)3]—showed sensitized metal‐centred emission (5D0→7FJ; J=0,1,2,3, 4, 5, or 6) in the visible region, upon irradiation of the ligand‐centred band at 369 nm, with the 5D0→7F0 transition centred at 580.9 nm. Spectral hole‐burning (SHB) studies of the complex with stoichiometric Eu(III) concentration revealed a narrow homogeneous linewidth (Γh) of 1.55 MHz corresponding to a 0.205 μs long optical coherence lifetime (T2opt). Remarkably, long nuclear spin lifetimes (T1spin) of up to 41 s have been observed for the complex. The narrow optical linewidths and long T1spin lifetimes obtained for the Eu(III) complex showcase the utility of Eu(III) complexes as tuneable, following molecular engineering principles, coherent light‐matter interfaces for QIP applications.
Funder
Deutsche Forschungsgemeinschaft