Crystalline Small Molecule‐Polymer Superlattice for Spatially Isolated Tetrathiafulvalene Spin Qubit Arrays
Linkuo Li, Zhecheng Sun, Xin Wang, Lei Zhang, Zihao Chen, Qianfeng Gu, Jinglun Yang, Yifan Cui, Yung‐Kang Peng, Lei Sun, Qichun ZhangABSTRACT
Molecular electron spins are compelling qubit candidates; however, mitigating their rapid relaxation and decoherence driven by structural disorder and phonon coupling remains a central challenge. Constructing molecular qubit frameworks (MQFs) represents a promising strategy to preserve quantum coherence by embedding spin centers in a rigid and ordered microenvironment. Here, we report a host–guest superlattice MQF by cocrystallizing tetrathiafulvalene (TTF) with a one‐dimensional B←N coordination polymer ( CityU‐65 ). Encaging TTF radical spins within this highly ordered lattice establishes a rigid and magnetically dilute environment, effectively suppressing spin‐lattice relaxation and partially mitigating spin decoherence. Consequently, CityU‐65 preserves coherent spin addressability even under ambient conditions. At room temperature, the superlattice exhibits a prolonged spin–lattice relaxation time ( T 1 = 9.6 µs) and a modestly improved phase‐memory time ( T m = 0.9 µs) compared to pristine crystalline TTF. Our work establishes B←N superlattice cocrystallization as a powerful strategy for engineering designer quantum materials, providing a general guideline for the development of high‐performance organic qubits through structural and phononic modulation.