论文标题
晶体中稀土离子的最低能量kramer态和磁性G因子的量子计算
Quantum computation of lowest-energy Kramers states and magnetic g-factors of rare earth ions in crystals
论文作者
论文摘要
我们介绍了两个稀土离子的基态能量和磁性G因子的量子计算的结果：Y2TI2O7晶体中的Yb3+和YPO4晶体中的ER3+。变量量子本元（VQE）算法已通过IBM量子体验云访问在5 Q Q Qubit IBM超导量子计算机上进行。每个Re离子最低光谱多重的哈密顿量（包含晶体场和Zeeman相互作用）已被投影到三个（Yb3+）和四个（ER3+）耦合的Transmon Qubits的集体状态。在算法的250次迭代中，在量子模拟器上执行的第一部分和最后25个迭代，在实际量子计算硬件上，发现了最低的离子能量状态。所有计算出的基态能量和磁性G因子与它们的确切值吻合，而估计的2÷15％的估计误差主要归因于与两Q量操作相关的变形。
We present the results of the quantum calculation of the ground state energies and magnetic g-factors of two rare earth (RE) ions: Yb3+ in Y2Ti2O7 crystal and Er3+ in YPO4 crystal. The Variational Quantum Eigensolver (VQE) algorithm has been performed on 5-qubit IBM superconducting quantum computer via IBM Quantum Experience cloud access. The Hamiltonian of the lowest spectroscopic multiplet of each RE ion, containing crystal field and Zeeman interaction, has been projected to the collective states of three (Yb3+) and four (Er3+) coupled transmon qubits. The lowest-energy states of RE ions have been found minimizing the mean energy in ~ 250 iterations of the algorithm: the first part performed on a quantum simulator, and the last 25 iterations - on the real quantum computing hardware. All the calculated ground-state energies and magnetic g-factors agree well with their exact values, while the estimated error of 2÷15% is mostly attributed to the decoherence associated with the two-qubit operations.
