Nonadiabatic time-dependent spin-density functional theory for strongly correlated systems

Area of Science:

• Quantum Chemistry
• Condensed Matter Physics
• Computational Materials Science

Background:

• Strongly correlated electron systems present significant challenges for standard electronic structure methods.
• Accurate modeling of excited states and ultrafast dynamics is crucial for understanding material properties.

Purpose of the Study:

• To introduce a novel nonadiabatic time-dependent spin-density functional theory (TDSDFT) approach.
• To enable the study of single-electron excited states and ultrafast responses in strongly correlated systems.

Main Methods:

• Developed a nonadiabatic exchange-correlation (XC) kernel using exact results from the Hubbard model.
• Applied the new TDSDFT formalism to Hubbard dimer and multi-dimensional Hubbard models.

Main Results:

• The nonadiabatic XC kernel successfully reproduces key spectral features of various Hubbard models.
• The approach captures spectral characteristics unattainable with adiabatic methods.

Conclusions:

• The proposed nonadiabatic TDSDFT formalism offers a powerful tool for ab initio studies of strongly correlated systems.
• This method extends the applicability of TDSDFT to systems beyond simple metals and semiconductors, including plasmons and excitons.