Extending Phenomenological Crystal-Field Methods to C_{1} Point-Group Symmetry: Characterization of the Optically Excited Hyperfine Structure of ^{167}Er^{3+}:Y_{2}SiO_{5}

Spectral and temporal atomic coherence interaction in Eu3+ : NaYF4 and Eu3+ : BiPO4

We investigate the spectral and temporal atomic coherence interaction based on out-of-phase fluorescence (FL) and spontaneous parametric four-wave mixing (SFWM) from the hexagonal phase of Eu3+ : NaYF4 and different phases of Eu3+ : BiPO4. Spectral and temporal interactions are interrelated and reduced by about 2 times due to two-photon nested dressing in contrast to the sum of each laser excitation. As the lifetime of photons increases, off-resonance profile cross-interaction decreases because cross-interaction reverses the signal at the near time gate position and keeps it consistent at the far time gate position. Moreover, the thermal phonon dressing at 300 K exhibits 6 times more eminent and obvious temporal interaction than that at 77 K. In a different phase of Eu3+ : BiPO4, there are three dark dips having stronger self-interaction; however, Eu3+ : NaYF4 has two dark dips as Eu3+ : BiPO4 has two phonon dressing. Further, the pure hexagonal phase of Eu3+ : BiPO4 demonstrates the strongest cross-interaction and longest coherent time under the dressing effect due to the smallest dressing phonon detuning and off-resonance profile cross-interaction at PMT2 because the angle quantization is the strongest. Such results can be used for designing novel quantum devices and have potential applications in quantum memory devices.

Zeeman spectroscopy and crystal-field analysis of low symmetry centres in Nd3+doped Y2SiO5

We report on infrared to visible Zeeman absorption spectroscopy and parameterised crystal-field modelling of Nd³⁺centres in Y₂SiO₅through the use of experimentally inferred crystal-field energy levels and Zeeman directional electronicgvalues. We demonstrate that good agreement between the calculated and experimental crystal-field energy levels as well as directional Zeemangvalues along all three crystallographic axes can be obtained. Further, we demonstrate that the addition of correlation crystal field effects successfully account for discrepancies that arise between the calculated and experimental values relevant to the²H11/2(2) multiplet in a one-electron crystal field model.

Zeeman and laser site selective spectroscopy of C1point group symmetry Sm3+centres in Y2SiO5: a parametrized crystal-field analysis for the 4f5configuration

Parametrized crystal-field analyses are presented for both the six and seven fold coordinated, C₁symmetry Sm³⁺centres in Y₂SiO₅, based on extensive spectroscopic data spanning the infrared to optical regions. Laser site-selective excitation and fluorescence spectroscopy as well as Zeeman absorption spectroscopy performed along multiple crystallographic directions has been utilized, in addition to previously determinedgtensors for the⁶H_5/2Z₁and⁴G_5/2A₁states. The resultant analyses give good approximation to the experimental energy levels and magnetic splittings, yielding crystal-field parameters consistent with the few other lanthanide ions for which such analyses are available.

Investigation of the Electronic Structure and Optical, EPR, and ODMR Spectroscopic Properties for 171Yb3+-Doped Y2SiO5 Crystal: A Combined Theoretical Approach

Various spectroscopic properties of Yb³⁺-doped Y₂SiO₅ crystal have been extensively investigated due to its promising application in quantum information processing. However, the local structure, electronic structure of Yb³⁺:Y₂SiO₅ crystal, and its optical and magnetic properties have not been comprehensively studied from a theoretical viewpoint. In this work, the geometric and electronic structures of Yb³⁺ that replaces two crystallographic Y³⁺ sites in the Y₂SiO₅ crystal are first obtained by the method of density functional theory (DFT). Then, the optical, electron paramagnetic resonance (EPR), and optically detected magnetic resonance (ODMR) spectra for ¹⁷¹Yb³⁺ (nuclear spin I = 1/2) at such two sites are simultaneously calculated in the framework of the complete diagonalization (of energy) matrix (CDM) based on the optimized local structure around ¹⁷¹Yb³⁺ ion by DFT. The various calculated spectroscopic properties by such combined theoretical approach are consistent with the experimental ones, which demonstrates that CDM is effective and particularly suitable for calculating hyperfine A-tensors under zero, low, and intermediate magnetic field. More importantly, based on the obtained accurate hyperfine structure of ¹⁷¹Yb³⁺ in Y₂SiO₅ crystal, the possible "clock transitions", which can enhance the optical coherence time, can be assigned or predicted by the present approach. This study successfully explains the spectroscopic properties of ¹⁷¹Yb³⁺-doped Y₂SiO₅ and provides a feasible method to design and search for practical rare-earth-doped quantum information materials for the community.