Embedding non-collinear two-component electronic structure in a collinear quantum environment

Area of Science:

• Computational physics and chemistry
• Materials science
• Quantum mechanics

Background:

• Spin-containing materials are crucial for advancing spintronic devices.
• Accurate modeling of spin interactions in complex environments is challenging.
• Existing computational methods may not fully capture the interplay between quantum subsystems and magnetic fields.

Purpose of the Study:

• To present a novel computational framework for embedding nonrelativistic, two-component quantum calculations within a one-component environment.
• To incorporate embedding scalar potentials and magnetic fields to simulate interactions between quantum subsystems.
• To investigate the impact of embedding on the spin structure of quantum systems.

Main Methods:

• Development of a computational framework embedding generalized Kohn-Sham density functional theory (DFT) electronic structure within unrestricted Kohn-Sham DFT.
• Inclusion of embedding scalar potential and magnetic field terms to model subsystem interactions.
• Application of the framework to study Li3 on a closed-shell He lattice and a Li3 on a He lattice with a Li atom defect.

Main Results:

• Embedding Li3 in a closed-shell He lattice via scalar potential did not alter its noncollinear spin structure.
• A Li atom defect in the He lattice introduced an effective magnetic field, influencing the embedded system's spin.
• Demonstrated that noncollinear quantum embedding in an open-shell collinear environment can modify spin structures.

Conclusions:

• The developed computational framework effectively models quantum subsystem interactions, including magnetic fields.
• The study highlights the significant impact of open-shell defects and magnetic fields on spin structures in embedded systems.
• This formalism offers a valuable tool for simulating inhomogeneous magnetic fields in two-component quantum calculations for materials science and spintronics.