Rational Construction of Layered Two-Dimensional Conjugated Metal-Organic Frameworks with Room-Temperature Quantum Coherence

Abstract

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have emerged as an intriguing class of quantum materials due to their high crystallinity, persistent spin centers, and tunable structures and topologies. However, it remains unclear how to achieve long spin relaxation time at room temperature in 2D c-MOFs via a bottom-up design strategy. Herein, we design a hexahydroxytrithiatruxene ligand (HHTH) to minimize the influence of nuclear spin on electron spin relaxation while weakening d-π conjugation to construct a “spin docking” for preserving spin centers, which enables the resulting 2D c-MOFs, Ni3HHTH2, to exhibit quantum coherence and Rabi oscillations at room temperature. Spin dynamics studies not only reveal an unusual temperature-dependent Rabi frequency in Ni3HHTH2 but also indicate that the coordination mode determines the spin-lattice relaxation behavior via spin-phonon coupling. These investigations provide a general guideline for the development of high-performance quantum qubits based on 2D spin arrays.