Characterization of the hyperfine interaction of the excited $^5$D$_0$ state of Eu$^{3+}$:Y$_2$SiO$_5$

TL;DR

This paper precisely characterizes the hyperfine interaction of Eu$^{3+}$ in Y$_2$SiO$_5$, providing essential parameters for quantum memory applications by measuring hyperfine splittings under weak magnetic fields.

Contribution

It determines the effective spin Hamiltonian parameters of Eu$^{3+}$'s excited state, enabling prediction of optical transition probabilities for quantum memory schemes.

Findings

Measured hyperfine splittings under magnetic fields up to 10 mT

Determined spin Hamiltonian parameters for Eu$^{3+}$ in Y$_2$SiO$_5$

Discussed implications for optical quantum memory

Abstract

We characterize the Europium (Eu$^{3+}$) hyperfine interaction of the excited state ($^5$D$_0$) and determine its effective spin Hamiltonian parameters for the Zeeman and quadrupole tensors. An optical free induction decay method is used to measure all hyperfine splittings under weak external magnetic field (up to 10 mT) for various field orientations. On the basis of the determined Hamiltonian we discuss the possibility to predict optical transition probabilities between hyperfine levels for the $^7$F$_{0} \longleftrightarrow ^5$D$_{0}$ transition. The obtained results provide necessary information to realize an optical quantum memory scheme which utilizes long spin coherence properties of $^{151}$Eu$^{3+}$:Y$_2$SiO$_5$ material under external magnetic fields