Radical Polymers for Simultaneous Singlet, Doublet, and Triplet Emission and Extended Spin Coherence Time

Luminescent radical materials with multiple spin states hold immense potential for applications in quantum information processing and spin optoelectronics, however research in this area remains limited. In this work, we report the first example of radical polymers that simultaneously exhibit singlet, doublet, and triplet state emissions at room temperature. We observed that incorporating radicals into polymers significantly amplifies the emission of triplet states, likely due to the facilitation of intersystem crossing by the radicals, efficiently mediating transitions from excited singlet states to triplet states. The direct optical readout of triplet state luminescence suggests the potential for building a spin-optical interface. Furthermore, these polymers demonstrate an extended spin coherence time of approximately 400 ns at room temperature. These findings indicate the promise of these materials for advancing quantum information storage and spin optoelectronics.