Zhou Aimei, Li Denan, Tan Mingshu, Lv Yanpei, Pang Simin, Zhao Xinxing, Shi Zhifu, Zhang Jun, Jin Feng, Liu Shi, Sun Lei
Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang Province, China.
Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang Province, China.
Nat Commun. 2024 Dec 30;15(1):10763. doi: 10.1038/s41467-024-54989-2.
The solid-state integration of molecular electron spin qubits could promote the advancement of molecular quantum information science. With highly ordered structures and rational designability, microporous framework materials offer ideal matrices to host qubits. They exhibit tunable phonon dispersion relations and spin distributions, enabling optimization of essential qubit properties including the spin-lattice relaxation time (T) and decoherence time. In this study, through spin dynamic and vibrational spectroscopic characterizations of two radical-embedded framework materials, we show that hydrogen-bonded networks give rise to a low Debye temperature of acoustic phonons and generates sub-terahertz optical phonons, both of which facilitate spin-lattice relaxation. Whereas deuterating hydrogen-bonded networks reduces both phonon frequencies and T, eliminating such flexible structural motifs raises phonon dispersions and improves the T by one to two orders of magnitude. The phononic tunability of spin-lattice relaxation in molecular qubit frameworks would facilitate the development of solid-state qubits operating at elevated temperatures.
分子电子自旋量子比特的固态集成可推动分子量子信息科学的发展。微孔框架材料具有高度有序的结构和合理的可设计性，为承载量子比特提供了理想的基质。它们表现出可调谐的声子色散关系和自旋分布，能够优化包括自旋 - 晶格弛豫时间（T）和退相干时间在内的基本量子比特特性。在本研究中，通过对两种嵌入自由基的框架材料进行自旋动力学和振动光谱表征，我们表明氢键网络导致声学声子的德拜温度较低，并产生亚太赫兹光学声子，这两者都有助于自旋 - 晶格弛豫。而对氢键网络进行氘化会降低声子频率和T，消除这种灵活的结构基序会提高声子色散并将T提高一到两个数量级。分子量子比特框架中自旋 - 晶格弛豫的声子可调谐性将有助于开发在高温下运行的固态量子比特。
