Advancing Room-Temperature Spin Qubits with Naphthalene Diimide-Based Chiral Covalent Organic Frameworks

Advancing the development of qubits with room-temperature coherence is crucial for realizing and democratizing quantum computing technologies. Here, we reveal for the first time that chiral covalent organic frameworks (CCOFs) serve as ideal hosts for electron spin qubits, exhibiting exceptionally long relaxation times at room temperature. The CCOF qubits (CCOF-Qs) were readily prepared via the condensation of enantiomeric naphthalene diimide (NDI) units bearing sp³-carbon chiral centers with triformylphloroglucinol, followed by cobaltocene reduction. At room temperature, CCOF-Q exhibits a spin relaxation time (T₁) of 160.5 μs, exceeding most molecular qubit frameworks (MQFs) and other classes of molecular qubits. More importantly, the phase memory time (T_m) of CCOF-Q reaches 1.7 μs, surpassing the record for MQFs. This superior spin qubit performance arises from suppressed spin-spin coupling due to staggered stacking with large interlayer distances within the chiral frameworks, and suppressed spin-phonon coupling owing to the inherent structural rigidity of CCOFs and the delocalized spins on the NDI units. Spin dynamic analysis reveals similar qubit behaviors in the two enantiomeric CCOFs, which are superior to their racemic counterpart. Together, this work demonstrates that the strategic incorporation of homochiral motifs into COF structures significantly enhances spin qubit performance, opening new avenues for quantum information science.