Quasiparticle electronic structure of copper in the GW approximation

Area of Science:

• Condensed Matter Physics
• Quantum Chemistry

Background:

• Photoemission and inverse photoemission experiments probe electronic structure.
• Discrepancies exist between experimental data and density functional theory (DFT) Kohn-Sham eigenvalues for bulk copper.
• The single-quasiparticle approximation is often assumed in theoretical descriptions.

Purpose of the Study:

• To quantitatively describe photoemission and inverse photoemission experimental results for bulk copper using band-structure theory.
• To investigate the role of self-energy effects in correcting theoretical band structures.
• To identify the importance of specific exchange-correlation contributions.

Main Methods:

• Utilizing band-structure theory for theoretical calculations.
• Applying self-energy corrections to Kohn-Sham eigenvalues.
• Analyzing exchange-correlation contributions, particularly from 3s and 3p core levels.

Main Results:

• Experimental results for bulk copper are quantitatively reproduced by band-structure theory.
• Self-energy effects significantly correct the discrepancies between experimental band structures and DFT Kohn-Sham eigenvalues.
• Exchange-correlation contributions from 3s and 3p core levels are identified as critical for this correction.

Conclusions:

• Band-structure theory, including self-energy effects, provides an accurate description of photoemission experiments on copper.
• The single-quasiparticle approximation is valid for describing these experimental results.
• Core-level exchange-correlation effects are essential for reconciling theoretical predictions with experimental observations in copper.