Opto-Spintronics: Photoisomerization-Induced Spin State Switching at 300 K in Photochrome Cobalt-Dioxolene Thin Films.
Opto-Spintronics: Photoisomerization-Induced Spin State Switching at 300 K in Photochrome Cobalt-Dioxolene Thin Films.
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DOI：
10.1021/jacs.8b09190
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发表时间：
2018-10
影响因子：
15
通讯作者：
M. Paquette;Daniel Plaul;Aiko Kurimoto;B. Patrick;N. Frank
中科院分区：
文献类型：
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作者：
M. Paquette;Daniel Plaul;Aiko Kurimoto;B. Patrick;N. Frank
可控量子系统正在积极研究量子计算、安全信息处理和非易失性存储器。自旋量子态的光学操纵为时间和空间分辨率的量子控制提供了重要的策略。提高 T > 200 K 下光致磁态寿命的挑战阻碍了在量子器件结构中利用光磁材料的进展。在这里，我们演示了在 300-330 K 的器件工作温度下有机薄膜中的可逆光诱导磁化转变。通过利用在固态下发生结构变化的光致变色配体，与光异构化相关的配体场的变化调节配体场，进而调节结合金属中心的氧化和自旋态。螺恶嗪钴二氧杂环戊烯络合物的绿光照射（λexc = 550 nm）会诱导配体发生光异构化，进而触发钴中心的可逆分子内电荷转移耦合自旋跃迁过程。通过低自旋 Co(III)-半醌双峰和高自旋 Co(II)-双半醌六峰之间的转换产生光磁态已在溶液和固态中得到证明，并被描述为光异构化诱导的自旋电荷激发态 (PISCES) 过程。高转变温度 (325 K) 和长寿命光诱导态 (τ = 10 s at 300 K) 由光致变色配体决定。理论提供了对该现象的有效建模和长期策略，以在单分子水平上进一步调节量子信息技术的光磁态寿命。
Controllable quantum systems are under active investigation for quantum computing, secure information processing, and nonvolatile memory. The optical manipulation of spin quantum states provides an important strategy for quantum control with both temporal and spatial resolution. Challenges in increasing the lifetime of photoinduced magnetic states at T > 200 K have hindered progress toward utilizing photomagnetic materials in quantum device architectures. Here we demonstrate reversible light-induced magnetization switching in an organic thin film at device operating temperatures of 300-330 K. By utilizing photochromic ligands that undergo structural changes in the solid state, the changes in ligand field associated with photoisomerization modulate the ligand field and in turn the oxidation and spin state of a bound metal center. Green light irradiation (λexc = 550 nm) of a spirooxazine cobalt-dioxolene complex induces photoisomerization of the ligand that in turn triggers a reversible intramolecular charge-transfer coupled spin-transition process at the cobalt center. The generation of photomagnetic states through conversion between a low-spin Co(III)-semiquinone doublet and a high-spin Co(II)-bis-semiquinone sextet state has been demonstrated in both solution and the solid state and is described as a photoisomerization-induced spin-charge excited state (PISCES) process. The high transition temperature (325 K) and long-lived photoinduced state (τ = 10 s at 300 K) are dictated by the photochromic ligand. Theory provides effective modeling of the phenomenon and long-term strategies to further modulate the lifetimes of photomagnetic states for quantum information technologies at the single molecule level.