Gd-Based Single-Ion Magnets with Tunable Magnetic Anisotropy: Molecular Design of Spin Qubits
Gd-Based Single-Ion Magnets with Tunable Magnetic Anisotropy: Molecular Design of Spin Qubits
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DOI：
10.1103/physrevlett.108.247213
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发表时间：
2012-06-15
影响因子：
8.6
通讯作者：
Luis, F.
中科院分区：
文献类型：
--
作者：
Martinez-Perez, M. J.;Cardona-Serra, S.;Luis, F.
我们报告交流磁化率和连续波和脉冲EPR实验进行GdW 10和GdW 30聚氧乙烯簇，其中Gd 3+离子是协调不同的聚氧乙烯部分。尽管钆作为自由离子的各向同性特征，这些分子在非常低的温度下显示出缓慢的磁弛豫，这是单分子磁体的特征。对于小于或类似于200 mK的T，自旋-晶格弛豫变得由纯量子隧穿事件主导，其速率与Prokof'ev和Stamp模型[Phys. Rev. Lett. 80，5794（1998）]。磁各向异性的符号、能级分裂和隧穿率强烈地依赖于分子结构。我们认为GdW 30分子也是有前途的自旋量子比特，其相干优值Q（M）大于或接近50。
We report ac susceptibility and continuous wave and pulsed EPR experiments performed on GdW10 and GdW30 polyoxometalate clusters, in which a Gd3+ ion is coordinated to different polyoxometalate moieties. Despite the isotropic character of gadolinium as a free ion, these molecules show slow magnetic relaxation at very low temperatures, characteristic of single molecule magnets. For T less than or similar to 200 mK, the spin-lattice relaxation becomes dominated by pure quantum tunneling events, with rates that agree quantitatively with those predicted by the Prokof'ev and Stamp model [ Phys. Rev. Lett. 80, 5794 (1998)]. The sign of the magnetic anisotropy, the energy level splittings, and the tunneling rates strongly depend on the molecular structure. We argue that GdW30 molecules are also promising spin qubits with a coherence figure of merit Q(M) greater than or similar to 50.