First principles studies of defect centers in two-dimensional NaCl associated with spin qubits

Spin defects in solids offer promising quantum bits (qubits) for quantum applications. However, the precise control of defect centers in three-dimensional (3D) crystals remains challenging. In contrast, two-dimensional (2D) materials provide a superior platform for both the controlled creation and precise manipulation of defect qubits. This work employs first-principles calculations to demonstrate that 2D NaCl exhibits high stability, a wide bandgap, and negligible spin–orbit coupling, making it a potential candidate for qubit host material. Among the eleven designed defects in 2D NaCl, the SeClVNa defect exhibits advantages of spin triplet ground states, spin conservation in optical transitions, and the excited state energy of the dark state is higher than that of its triplet bright state. However, the critical qubit operation parameter, the zero-phonon line, remains relatively small. Notably, the zero-field splitting of the SeClVNa defect falls within the microwave range, which is particularly suitable for quantum manipulation. Finally, the hyperfine tensors are calculated to assess the interaction between electron spin and nuclear spin. This study provides fundamental insights into the design principles of solid-state spin qubits in 2D materials for quantum technology application.