Advances in Quantum Defect Embedding Theory

Area of Science:

• Condensed matter physics
• Quantum chemistry
• Materials science

Background:

• Quantum defect embedding theory (QDET) is a many-body method for localized electrons in condensed systems.
• Existing QDET limitations hinder accurate predictions for point defects like spin defects.

Purpose of the Study:

• To advance the Quantum defect embedding theory (QDET) formalism.
• To improve the accuracy and applicability of QDET for electronic property predictions.

Main Methods:

• Derived a frequency-dependent double-counting correction for screened Coulomb interactions.
• Incorporated unoccupied orbitals into the active space.
• Developed a method for active space-environment hybridization.
• Compared various impurity solvers.

Main Results:

• Demonstrated improved QDET predictions for defects in diamond.
• Applied enhanced QDET to molecular qubits.
• Provided detailed comparisons with experimental data.

Conclusions:

• The proposed QDET advancements enhance reliability for describing correlated electrons in materials.
• The refined theory offers better insights into defect properties and applications in quantum technologies.