Chinaegbomkpa Uchenna V, Huai Xudong, Winiarski Michal J, Sanabria Hugo, Tran Thao T
Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States.
Faculty of Applied Physics and Mathematics and Advanced Materials Center, Gdansk University of Technology ul. Narutowicza 11/12, Gdansk 80-233, Poland.
ACS Mater Au. 2024 Nov 5;5(1):182-190. doi: 10.1021/acsmaterialsau.4c00102. eCollection 2025 Jan 8.
Lanthanide materials with a 4f electron configuration (S) offer an exciting system for realizing multiple addressable spin states for qubit design. While the S ground state of 4f free ions displays an isotropic character, breaking degeneracy of this ground state and excited states can be achieved through local symmetry of the lanthanide and the choice of ligands. This makes Eu attractive as it mirrors Gd in exhibiting the S ground state, capable of seven spin-allowed transitions. In this work, we identify Eu(PS) and Eu(PSe) as viable candidates for optically addressable spin states. The materials feature paramagnetic behavior at 2.0 ≤ ≤ 400 K and μ = 0.01 and 7 T. The field-dependent magnetization () curve reveals a single-ion spin with effective magnetic moments comparable to the expected magnetic moment of Eu. Seven well-defined narrow peaks in the excitation and emission spectra of Eu are resolved. Phonon contributions to the Eu spin environment are evaluated through heat capacity measurements. Insights into how the spin-polarized band structure and density of states of the materials influence the physical properties are described by using density functional theory calculations. These results present a foundational study of Eu(PS) and Eu(PSe) as a feasible platform for harnessing the spin, charge, orbital, and lattice degrees of freedom of Eu for qubit design.
具有4f电子构型的镧系材料为量子比特设计中实现多个可寻址自旋态提供了一个令人兴奋的体系。虽然4f自由离子的基态S表现出各向同性特征，但通过镧系元素的局部对称性和配体的选择，可以打破该基态和激发态的简并性。这使得铕具有吸引力，因为它与钆类似，呈现基态S，能够进行七个自旋允许跃迁。在这项工作中，我们确定Eu(PS)和Eu(PSe)是光学可寻址自旋态的可行候选材料。这些材料在2.0≤T≤400 K和μ=0.01以及7 T时表现出顺磁行为。场依赖磁化强度（M）曲线揭示了一个单离子自旋，其有效磁矩与铕的预期磁矩相当。在铕的激发和发射光谱中分辨出七个定义明确的窄峰。通过热容测量评估了声子对铕自旋环境的贡献。利用密度泛函理论计算描述了材料的自旋极化能带结构和态密度如何影响物理性质。这些结果为将Eu(PS)和Eu(PSe)作为利用铕的自旋、电荷、轨道和晶格自由度进行量子比特设计的可行平台提供了基础研究。
