| Abstract [eng] |
The advent of quantum technologies has created new avenues in quantum computing, quantum communication, and quantum sensing. A key requirement for these applications is the ability to control quantum states with high fidelity. Solid-state platforms offer a scalable and robust basis for quantum systems, with point defects in semiconductors emerging as key candidates for quantum bits and single-photon emitters. Identifying and analyzing suitable defects requires accurate theoretical methods capable of predicting their electronic and optical properties. This thesis investigates the performance of the SCAN family of meta-GGA density functionals for first-principles modeling of point defects in semiconductors. The performance of the SCAN, rSCAN, and r²SCAN functionals is benchmarked against standard GGA and hybrid functionals in describing the electronic, vibrational, and vibronic properties of color centers in diamond, silicon, and 4H–SiC. Emphasis is placed on optical excitation energies, luminescence, and absorption lineshapes, with comparisons to experimental results. The SCAN family of functionals achieves accuracy comparable to hybrid functionals at significantly lower computational cost. These results establish the SCAN family of density functionals as a reliable and efficient tool for defect characterization and screening in solid-state materials. |
