Using Photoexcited Core/Shell Quantum Dots To Spin Polarize Appended Radical Qubits
Using Photoexcited Core/Shell Quantum Dots To Spin Polarize Appended Radical Qubits
复制标题
使用光激发核/壳量子点来旋转极化附加的自由基量子位
DOI：
10.1021/jacs.0c06073
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发表时间：
2020
影响因子：
15
通讯作者：
Wasielewski, Michael R.
中科院分区：
文献类型：
--
作者：
Olshansky, Jacob H.;Harvey, Samantha M.;Pennel, Makenna L.;Krzyaniak, Matthew D.;Schaller, Richard D.;Wasielewski, Michael R.
半导体量子点（QD）的合成可调性、灵活性和丰富的自旋物理特性使其成为量子信息科学应用的有希望的候选者。然而，在胶体量子点中观察到的快速自旋弛豫限制了它们的功能。在当前的工作中，我们演示了一种利用量子点中的光激发自旋态在附加的有机配体分子上产生长寿命自旋极化的方法。我们提出了一种由 CdSe/CdS 核/壳 QD 组成的系统，该系统与萘二亚胺 (NDI) 电子接受分子共价连接。探索了从光激发 QD 到附加 NDI 配体的电子转移动力学，作为壳厚度和每个 QD NDI 数量的函数。瞬态 EPR 光谱表明，光激发 QD 强烈自旋极化 NDI 自由基阴离子，这可以在自旋极化的自由基对和三重态机制的背景下进行解释。这项工作是使用光激发量子点对具有长自旋弛豫时间的有机自由基进行强自旋极化，以在量子信息科学应用中充当自旋量子位的第一步。
The synthetic tunability, flexibility, and rich spin physics of semiconductor quantum dots (QDs) make them promising candidates for quantum information science applications. However, the rapid spin relaxation observed in colloidal quantum dots limits their functionality. In the current work, we demonstrate a method to harness photoexcited spin states in QDs to produce long-lived spin polarization on an appended organic ligand molecule. We present a system composed of CdSe/CdS core/shell QDs, covalently linked to naphthalenediimide (NDI) electron-accepting molecules. The electron transfer dynamics from photoexcited QDs to the appended NDI ligands is explored as a function of both shell thickness and number of NDIs per QD. Transient EPR spectroscopy shows that the photoexcited QDs strongly spin polarize the NDI radical anion, which is interpreted in the context of both the radical pair and the triplet mechanisms of spin polarization. This work serves as an initial step toward using photoexcited QDs to strongly spin polarize organic radicals having long spin relaxation times to serve as spin qubits in quantum information science applications.