Observation of Narrow Optical Homogeneous Linewidth and Long Nuclear Spin Lifetimes in a Prototypical [Eu(trensal)] Complex

Coherentlight-matter interfaces are key elements for manyquantum information processing architectures. Rare-earth ion (REI)-containingsystems featuring narrow inter-configurational f-f transitionsare suitable for creating such interfaces. Recently, narrow homogeneouslinewidths (& UGamma;(h)) and long nuclear spin lifetimes (T (1spin)) associated with two Eu3+ complexesfeaturing the D-5(0) & RARR; F-7(0) f-f transition have been reported, elucidating thatREI-molecule-based coherent light-matter interfaces can beobtained. In this study, we report a homogeneous linewidth of 2.8MHz at 4.2 K, corresponding to an optical coherence lifetime (T (2opt)) of 114 ns (0.11 & mu;s), associatedwith the D-5(0) & RARR; F-7(0) transition of the prototypical charge neutral Eu3+ complex R[Eu-(trensal)].Moreover, we have observed long nuclear spin lifetimes (T (1spin)) up to 460 & PLUSMN; 80 s at 4.2 K for the complexand efficient optical pumping of hyperfine levels of the D-5(0) ground state. The results presented in this study indicatethat narrow homogeneous linewidths and long nuclear spin lifetimescould be a generic property of molecular Eu3+ complexesfeaturing the D-5(0) & RARR; F-7(0) transition.