Quantum defects in two-dimensional van der Waals materials.

Quantum defects in solid materials, such as nitrogen-vacancy color centers in diamond, have been extensively studied and successfully demonstrated as single photon emitters and potential qubits for quantum computers. However, a major challenge has always been positioning these quantum defects near the sample surface for measuring or sensing purposes. The emergence of quantum defects in two-dimensional (2D) van der Waals (vdW) materials open up new opportunities for overcoming these limitations. These materials possess unique properties, including vdW interlayer coupling and clean surfaces without unsaturated dangling bonds, which provide greater advantages for manufacturing multi-qubit systems. In this review, we present the research progress on quantum defects in 2D vdW materials, covering quantum guidelines for spin defects in solid state, the latest demonstrations of quantum defects, the unique methods and techniques for generating and modulating defects in 2D vdW materials.